“You never asked doc., I do fish”

Joint pains and swellings are routine complaints in rheumatology clinics. Infectious diseases may mimic common rheumatic conditions and thus need to be ruled out before initiating any immunosuppressive treatment. Mycobacterium marinum is an organism that can present with a typical arthritis picture. A 60-year-old gentleman with a complicated medical history presented with a right wrist swelling which was initially managed as a case of remitting seronegative arthritis. He eventually required tenolysis and the biopsy showed M. marinum. On inquiry, he was found to be an avid fisherman. This report discusses typical diagnostic pitfalls, literature review on the reported cases and treatment strategies. The most important point is to ask for occupational and hobby history in such cases.