Vibrio anguillarum and Lactococcus garvieae which causes mixed infections were isolated for the first time from rainbow trout farms in the Southwest of Turkey. The outbreak occurred at 15 degrees C water temperature in June 2009. The diseased fish showed erratic swimming, dark discoloration, bilateral exopthalmia, haemorhages on the fins, operculum, the liver, spleen and lower intestines with mortality ranging from 30-50% in the pools. The identities of the isolates were confirmed as V. anguillarum O1 and L. garvieae by biochemical and serological tests using API 20 Strep, API 20 E and API Strept system test strips and also V. anguillarum (ATTC 43305) used as antigens for agglutination. The epizootic disease was effectively controlled by oral administration of enrofloxacin.