A seven-year-old intact male chinchilla presented for evaluation of progressive skin lesions for 6+ months. The referring veterinarian had submitted a ringworm PCR which was negative and attempted treatment with antibiotics with minimal improvement. At presentation the patient had extensive lesions but the most severe were over the entire face, nose, ears, feet, and tail with significant hair loss, swollen thickened skin, crusts, and ulcerations. The patient was thin and both tarsal joints were fused at 90 degrees. Because of the failure of previous treatment and the unusual presentation, the patient was anesthetized and skin biopsy samples were obtained. Histopathology indicated severe pyogranulomatous dermatitis with acid-fast, rod-shaped bacteria consistent with Mycobacterium spp. Because of the severity of the patient’s signs and zoonotic potential, the patient was humanely euthanized and submitted for full necropsy. Nodules were also present in the lungs, but there were no other gross lesions. On histopathology, the diagnosis was confirmed and the pulmonary nodules were granulomas with acid-fast bacteria. Mycobacterial culture was attempted but there was no growth after 10 weeks. PCR testing revealed M. szulgai as the causative agent. M. szulgai has been reported to cause pulmonary and cutaneous lesions in humans, but is quite rare. There are only three case reports published confirming disease caused by this organism in any animal species, and this is only the second report of infection in a chinchilla caused by any Mycobacterium species.