CSI may stand for:

  • California Spine Institute
  • California Steel Industries Inc.
  • Canadian Securities Institute (csi.ca)
  • Canadian Seed Institute
  • Canadian Sugar Institute
  • Cardiological Society of India
  • Carrier Scale Internetworking
  • Cast Stone Institute
  • Causal side information
  • Center for Sports Innovation (MIT)
  • Center for the Study of Intelligence (CIA)
  • Cetacean Society International
  • Chemical shift imaging
  • Chicago Systemic Initiative
  • Christian Schools International
  • Christian Solidarity International
  • Christian Sports International
  • Church of Scientology International
  • Church of South India
  • Coalition of Service Industries
  • Collision Safety Institute
  • College of Staten Island
  • Combat Studies Institute (US Army)
  • Combat system integration
  • Command Systems, Inc
  • Commercial satellite imagery
  • Common software interface
  • Companion of The Most Exalted Order of the Star of India
  • Complex specified information
  • Compton scatter imaging
  • CompuServe Inc.
  • Computer Sales International Inc.
  • Computer Security Institute
  • Computer Society of India
  • Conditional symmetric instability
  • Construction Specifications Institute
  • Consumer Safety Inspector
  • Consumer Science Index
  • Convergence Solutions, Inc
  • Coral Sea Islands
  • CSI: Crime Scene Investigation (television series)
  • Cuban Studies Institute