---

Background & Objective: Mycobacterium marinum is the etiologic agent of fish Mycobacteriosis and fish tank granuloma in human in this study our objective was to determine of the fish tank granuloma in Fishermen and Mycobacterium marinum infection in Caviar fishes in Ashorade, in the Golestan province of Iran south east Caspian Sea border. Materials & Methods: Any suspected lesions in 387 subjects of Fishermen and 113 autopsy samples from gills of fish of Caviar were obtained and cultured in Lowenstein Jensen media. The mycobacterial species were determined by conventional biochemical tests. Results: No fish tank granuloma was proved in human, but 11 (9.73%) strains of Mycobacteria were isolated from Caviar fishes, that only 2 strains (1.76%) belong to M.marinum. Conclusion: This study showed that was low prevalence any cases of fish tank granuloma and infection due to M.marinum in Caviar fish in this Region.