• Worldwide Private Investigators and Detectives Directory 
  
  A very large directory of private investigators and private detectives worldwide. From Hieros Gamos.
  http://www.hierosgamos.org/hg/private_investigators.asp
• Private Investigator Directory 
  
  Sorted by State and by country for worldwide private investigator listings. From Infoguys.
  http://www.infoguys.com/directory.cfm
• Private Investigator Listings 
  
  National, state and local listings for private investigators. Easily narrow your search to a specific area. From Verizon Yellow Pages.
  http://yellowpages.superpages.com/listings.jsp

• Alabama Private Investigator Associations:
  
  • Alabama Professional Investigator's Association (APIA)
    
    http://www.apia-online.com/

• Alaska Private Investigator Associations:
  
  • Alaska Investigator's Association (AIA)
    
    http://www.akinvestigators.com/

• Arizona Private Investigator Associations:
  
  • Arizona Association of Licensed Private Investigators (AALPI)
    
    http://www.aalpi.org/

• Arkansas Private Investigator Associations:
  
  • Arkansas Association of Professional Private Investigators (AAPPI)
    
    http://www.aappi.org/

• California Private Investigator Associations:
  
  • California Association of Licensed Investigators (CALI)
    
    http://www.cali-pi.org/

• Colorado Private Investigator Associations:
  
  • Professional Private Investigators Association of Colorado (PPIAC)
    
    http://www.ppiac.org/

• Connecticut Private Investigator Associations:
  
  • Connecticut Association of Licensed Private Investigators (CALPI)
    
    http://users.ntplx.net/~calpi/

• Delaware Private Investigator Associations:
  
  • No websites found.
    

• District of Columbia Private Investigator Associations:
  
  • No websites found.
    

• Florida Private Investigator Associations:
  
  • Florida Association of Licensed Investigators (FALI)
    
    http://www.piaf.org/

• Georgia Private Investigator Associations:
  
  • Georgia Association of Professional Private Investigators (GAPPI)
    
    http://www.gappi.org/

• Hawai'i Private Investigator Associations:
  
  • No websites found.
    

• Idaho Private Investigator Associations:
  
  • Idaho Private Investigators Association (IPIA)
    
    http://www.ipiai.org/

• Illinois Private Investigator Associations:
  
  • Associated Detectives & Security Agencies of Illinois (ADSAI)
    
    http://www.the-adi.com/

• Indiana Private Investigator Associations:
  
  • Indiana Association of Professional Investigators (IAPI)
    
    http://www.iapi.net/

• Iowa Private Investigator Associations:
  
  • Iowa Association of Private Investigators (IAPI)
    
    http://www.iowa-investigators.com/

• Kansas Private Investigator Associations:
  
  • Kansas Association of Private Investigators (KAPI)
    
    http://www.kapi.org/

• Kentucky Private Investigator Associations:
  
  • Kentucky Professional Investigators Association (KPIA)
    
    http://www.kpia.org/

• Louisiana Private Investigator Associations:
  
  • Louisiana Private Investigators Association (LPIA)
    
    http://www.lpia.net/

• Maine Private Investigator Associations:
  
  • Maine Licensed Private Investigator's Association (MLPIA)
    
    http://www.mlpia.org/

• Maryland Private Investigator Associations:
  
  • Maryland Investigators and Security Association (MISA)
    
    http://www.misahq.com/

• Massachusetts Private Investigator Associations:
  
  • Licensed Private Detectives Association of Massachusetts (LPDAM)
    
    http://www.lpdam.org/

• Michigan Private Investigator Associations:
  
  • Michigan Council of Private Investigators (MCPI)
    
    http://www.mcpihome.com/

• Minnesota Private Investigator Associations:
  
  • Minnesota Association of Private Investigators and Protective Agents (MAPI)
    
    http://www.mapi.org/

• Mississippi Private Investigator Associations:
  
  • No websites found.
    

• Missouri Private Investigator Associations:
  
  • Missouri Association of Private Investigators (MAPI)
    
    http://www.mapi-inc.com/

• Montana Private Investigator Associations:
  
  • No websites found.
    

• Nebraska Private Investigator Associations:
  
  • No websites found.
    

• Nevada Private Investigator Associations:
  
  • No websites found.
    

• New Hampshire Private Investigator Associations:
  
  • New Hampshire League of Investigators (NHLI)
    
    http://www.nhli.net/

• New Jersey Private Investigator Associations:
  
  • New Jersey Licensed Private Investigators Association (NJLPIA)
    
    http://www.njlpia.org/

• New Mexico Private Investigator Associations:
  
  • No websites found.
    

• New York Private Investigator Associations:
  
  • Associated Licensed Detectives Of New York State (ALDONYS)
    
    http://www.aldonys.org/

• North Carolina Private Investigator Associations:
  
  • North Carolina Association of Private Investigators (NCAPI)
    
    http://www.ncapi.org/

• North Dakota Private Investigator Associations:
  
  • No websites found.
    

• Ohio Private Investigator Associations:
  
  • Ohio Investigators Association (OIA)
    
    http://www.oia.homestead.com/OIA.html

• Oklahoma Private Investigator Associations:
  
  • Oklohoma Private Investigators Association (OPIA)
    
    http://www.opia.com/

• Oregon Private Investigator Associations:
  
  • Oregon Association of Licensed Investigators (OALI)
    
    http://www.oali.org/

• Pennsylvania Private Investigator Associations:
  
  • Pennsylvania Association of Licensed Investigators (PALI)
    
    http://www.pali.org/

• Rhode Island Private Investigator Associations:
  
  • Licensed Private Detectives Association of Rhode Island (LPDARI)
    
    http://www.lpdari.org/

• South Carolina Private Investigator Associations:
  
  • South Carolina Association of Legal Investigators (SCALI)
    
    http://www.scalinv.com/

• South Dakota Private Investigator Associations:
  
  • No websites found.
    

• Tennessee Private Investigator Associations:
  
  • Tennessee Professional Investigators Association (TPIA)
    
    http://www.tpia.com/

• Texas Private Investigator Associations:
  
  • Texas Association of Licensed Investigators (TALI)
    
    http://www.tali.org/

• Utah Private Investigator Associations:
  
  • Private Investigators Association of Utah (PIAU)
    
    http://www.piau.com/p_home.asp

• Vermont Private Investigator Associations:
  
  • Vermont Association of Licensed Detectives (VPIA)
    
    http://www.pimall.com/vermont/

• Virginia Private Investigator Associations:
  
  • Private Investigators Association of Virginia (PIAVA)
    
    http://www.piava.org/

• Washington Private Investigator Associations:
  
  • Washington Association of Legal Investigators (WALI)
    
    http://www.wali.org/

• West Virginia Private Investigator Associations:
  
  • Private Investigators and Security Professionals of West Virginia (PISP)
    
    http://www.pispwv.org/

• Wisconsin Private Investigator Associations:
  
  • Professional Association of Wisconsin Licensed Investigators (PAWLI)
    
    http://www.pawli.com/

• Wyoming Private Investigator Associations:
  
  • No websites found.
    

     See also, these cross-references:

• Investigation Resources
  
• Court Reporters
  
• Expert Witnesses