BSI

BSI may refer to:

• The Baker Street Irregulars, a fictional group featured in Sherlock Holmes stories
• Banca della Svizzera Italiana
• Bentley Systems Inc.
• Bible Society of India
• BioShock Infinite, a 2013 first person shooter
• Bloodstream infection (see Bacteremia)
• Body substance isolation
• Botanical Survey of India
• British Society for Immunology
• British Solomon Islands, a former territory
• BSI Group or British Standards Institution, erroneously, 'British Standards Institute'
• Broadcast signal intrusion
• Bundesamt für Sicherheit in der Informationstechnik, the German Federal Office for Information Security
• Bureau of Special Investigation in Burma
• BSI coupling, a railroad coupling or coupler

Information technology

• Backside illumination, a type of digital image sensor
• Bridge Software Institute, University of Florida