- AAFI- Amateur Athletics of India
- AAPSO- Afro-Asian People’s Solidarity Organization
- AASU -All Assam Students Union
- ABM- Anti Ballistic Missile
- AC -Alternate Currency / Ashok Chakra / AirConditioner
- ACC- Anxillary Cadet Core
- AD -Ano Domini (After the birth of Jesus)
- ADB -Asian Development Bank
- AERE- Atomic Energy Research Establishment
- AGOC -Asian Games Organization Committee
- AICC -All India Congress Committee
- AICTE -All India Council of Technical Education
- AIDS- Acquired Imuno Deficiency Syndrome
- AIFE- All India Football Federation
- AIIMS- All India Institute of Medical Sciences
- AIL- Aeronautics India Limited
- AIMPLB- All India Muslim Personal Law Board
- AIR- All India Radio (Broadcasting)
- AITUC- All India Trade Union Congress
- AM- Anti Meridian (Before Noon)
- ANC- African National Congress
- APEC- Asia Pacific Economic Cooperation
- APSC- Army Postal services Core
- ASEAN- Association of South East Asian Nations
- ASLV- Augmented Satellite Launch Vehicle
- ASI -Archaeological Survey of India
- ASSOCHAM- Associated Chamber of Commerce
- and Industry (India)
- ASWAC -Airborne Surveillance Warning and Control
- ATS- Anti Tetanus Serum
