ASD
- ASD (album)
- ASD (database)
- Academy for Science and Design
- Acceleration spectral density
- Achievement School District
- Active sound design
- Acute stress disorder
- Adaptive software development
- AeroSpace and Defence Industries Association of Europe
- Aeronautical Systems Division
- Air Sinai
- Allentown School District
- Alliance for Securing Democracy
- Alliance for Social Democracy
- Allowable stress design
- American School for the Deaf
- American School of Doha
- American School of Douala
- American School of Dubai
- Amsterdam Centraal station
- Anchorage School District
- Andros Town International Airport
- Antiseptic Dorogov's Stimulator
- Application Specific Device
- Architectural Services Department
- Armstrong School District (Pennsylvania)
- Asas language
- Aspartate-semialdehyde dehydrogenase
- Aspirating smoke detector
- Atrial septal defect
- Australian Signals Directorate
- Autism spectrum disorder
- International Association for the Study of Dreams
- Microsoft Flight Simulator 4.0
- Slidell Airport
- United States Assistant Secretary of Defense