Cai
- CAIS (disambiguation)
- Cai (name)
- Cai (state)
- Cai (surname)
- Cairo International Airport
- Caithness
- Calcium–aluminium-rich inclusion
- Canadian Airlines International
- Capitol Archaeological Institute
- Carbonic anhydrase inhibitor
- Caí River
- Central Asia Institute
- Chartered Accountants Ireland
- Christian Assemblies International
- Club Alpino Italiano
- Club Atletico Independiente de La Chorrera
- Club Atlético Independiente
- Codon Adaptation Index
- Cold air intake
- Coleraine Academical Institution
- College of Anaesthesiologists of Ireland
- Comisión de Actividades Infantiles
- Community Associations Institute
- Compagnia Aerea Italiana
- Comprehensive Agreement on Investment
- Computer assisted instruction
- Computer-aided inspection
- Computer-assisted language learning
- Confederation of Australian Industry
- Conodont Alteration Index
- Content Authenticity Initiative
- Controlled Auto-Ignition
- Corendon Airlines
- Corpo Aereo Italiano
- Cái River (Khánh Hòa)
- Kai (disambiguation)
- Mesoamerican languages
- Sir Kay
- WCAI