Abstract: A 57-year-old female presented with nodules on her right upper limb for three months. Histological examination showed infectious granulomas. No spores and hyphae were found through PAS staining and acid-fast staining was negative. Mycobacterium marinum qPCR was positive. The diagnosis mycobacterium marinum infection was made and the lesions was subside after treated with doxycycline, clarithromycin and rifampicin.