We report the first case of a post-acupuncture soft tissue infection due to Mycobacterium fortuitum. Two months after finishing an acupuncture treatment session, an immunocompetent 23-year-old woman developed cellulitis at the side of the needle insertions and the acid-fast bacillus was isolated from a closed abscess. The patient was successfully treated with a proper drug combination. We review the literature concerning the infection source and the risks for skin and soft tissue infection due to mycobacteria after acupuncture. The infection source in most cases is unknown but is probably associated with the inadequate sterilization of the needles or the puncture site. We show that these infections are not rare but difficult to diagnose. To avoid delays in the definitive diagnosis, infection with mycobacteria should be considered for skin and soft tissue infections, in particular late-onset infections, which are negative for routine bacterial cultures and without a clinical response to antibiotics used for acute pyogenic infections. Bacterial cultures from this lesion should be maintained for at least six weeks before discharged as negative.