10.22376/ijpbs.2019.10.1.p1-12 Volume 4 Issue 3 2013 (July - September) Antimicrobial effect of the extract of three Indian mangrove plants of lessThan i greaterThan Avicennia officinalis lessThan /i greaterThan (stem) Fam. Avicennaceae, lessThan i greaterThan Rhizophora mucronata lessThan /i greaterThan , pior (root and stem) Fam. Rhizophoraceae and lessThan i greaterThan Sonneratia alba lessThan /i greaterThan J Smith (stem) Fam. Sonneratiaceae bark were investigated. The crude extracts from dried barks of mangroves were extracted in methanol and obtained extracts were evaporatorted to concentrate. The extract obtained was evaluated for antimicrobial activity against bacteria by using agar well diffusion method and the zone of inhibition in diameters was measured. The standard extracts at the concentration of 50µg/ml exhibited antibacterial activity against test microorganism. The root of lessThan i greaterThan R. mucronata lessThan /i greaterThan and stem extract of lessThan i greaterThan R. mucronata lessThan /i greaterThan , lessThan i greaterThan S. alba lessThan /i greaterThan and lessThan i greaterThan A. officinalis lessThan /i greaterThan exhibits highest antimicrobial activity showing zone of inhibition in the range 21-39mm against all tested bacteria. POWAR P. S. AND D. K. GAIKWAD Antibacterial activity, Avicennia sp, Mangrove, MIC, Rhizophora sp, Sonneratia sp. 149-152