Vibrio parahaemolyticus is a common pathogen causing food poisoning with lethal results. Composition of phytoplankton communities could be a possible source affecting survival, persistence and proliferation of V. parahaemolyticus in marine environments. In this experiment an environmental strain of V. parahaemolyticus, isolated from the southwest coast of India, was exposed to one dinoflagellate, Prorocentrum micans and one diatom, Skeletonema tropicum. Results show that P. micans facilitate and S. tropicum prevents persistence of V. parahaemolyticus.