A total of 21 meagre samples from a fish farm in southwestern Turkey was presented to our laboratory with anorexia, weight loss and mortality as symptoms. Necropsy revealed grey-white miliary lesions with multifocal distribution in various organs, especially liver, spleen and kidney. In histopathology, coalescing tubercles were observed on the same tissues. Mycobacterium marinum was isolated and identified from these fish as a result of bacteriological examination. Identification was carried out with the Genotype Mycobacterium CM (Hain Lifescience) kit. PCR products were sequenced and recorded in GenBank as Mycobacterium marinum.