Biomedical! images! published! within! the! scientific! literature! play! a! central! role! in! reporting! and! facilitating! life! science! discoveries.! Existing! ontologies! and! vocabularies! describing! biomedical! imagS es,! particularly! sequence! images,! do! not! provide! sufficient! semanS tic! representation! for! image! annotations! generated! automatically! and/or! semiSautomatically.! We! present! an! open! ontology! for! the! annotation! of! biomedical! images! (BIM)! scripted! in! OWL/RDF.! The! BIM! ontology! provides! semantic! vocabularies! to! describe! the! manually!curated!image!annotations!as!well!as!annotations!generS ated! by! online! bioinformatics! services! using! content! extracted! from! images! by! the! Semantic! Enrichment! of! Biomedical! Images! (SEBI)! system.! The! BIM! ontology! is! represented! in! three! parts;! (i)! image! vocabularies! S! which! holds! vocabularies! for! the! annotation! of! an! image! and/or! region! of! interests! (ROI)! inside! an! image,! as! well! as! vocabularies! to! represent! the! pre! and! post! processing! states! of! an! image,! (ii)! text! entities! S! covers! annotations! from! the! text! that! are! associated! with! an! image! (e.g.! image! captions)! and! provides!semantic!representation!for!NLP!algorithm!outputs,!(iii)!a! provenance! model! !S! that! contributes! towards! the! maintenance! of! annotation! versioning.! To! illustrate! the! BIM! ontology’s! utility,! we! provide! three! annotation! cases! generated! by! BIM! in! conjunction! with!the!SEBI!image!annotation!engine.