A 70-year-old patient developed Mycobacterium chelonae infection at a donor vein graft site following cardiac bypass surgery. The infection presented as fibrinous, necrotic ulcerations in the scar area. Mycobacterium chelonae and mycobacterium fortuitum are atypical mycobacteria and have been described previously causing infections after injections or surgical procedures. Infection of donor vein graft site is a rare complication after cardiac surgery. As mycobacterium chelonae cannot be cultivated on normal culture media, delayed wound healing might be disinterpretated as a primary wound healing disorder. Treatment of atypical myobacteriosis includes antibiotics, local heat therapy and surgical excision. Clarithromycin is the antibiotic of choice. We obtained complete healing after two months of Clarithromycin treatment, combined with heat therapy.