| Acronym | Definition |
|---|
| ATRA | All-Trans Retinoic Acid (aka tretinoin) |
| ATRA | American Tort Reform Association |
| ATRA | American Therapeutic Recreation Association (Alexandria, VA) |
| ATRA | Automatic Transmission Rebuilders Association |
| ATRA | Air Transport Rating Agency (Geneva, Switzerland) |
| ATRA | Advanced Transit Association |
| ATRA | Arizona Tax Research Association |
| ATRA | Alberta Tobacco Reduction Alliance |
| ATRA | Airedale Terrier Rescue and Adoption (Michigan) |
| ATRA | Alberta Therapeutic Recreation Association |
| ATRA | Assistive Technology Resource Alliance |
| ATRA | American Track Racing Association |
| ATRA | American Thai Ridgeback Association (Thai Ridgeback dog breed) |
| ATRA | Association Tortues Rhône-Alpes (French: Association of Rhone-Alps Tortoises |
| ATRA | Army Recruiting and Training Agency (UK MoD) |
| ATRA | Auto and Truck Recyclers Association |
| ATRA | Advanced Technology Reconnaissance Aircraft |
| ATRA | Afghan Telecommunications Regulatory Authority |