Infection caused by Leuconostoc spp. is very rare. We report a case of Leuconostoc bacteremia in a patient receiving antimycobacterial chemotherapy for pulmonary Mycobacterium xenopi infection. In addition, the patient presented several known characteristic predisposing factors associated with Leuconostoc infection, such as severe underlying disease, previous long-term antibiotic treatment, indwelling intravascular catheter, prolonged parenteral feeding, previous methicillin-resistant Staphylococcus epidermidis (MRSE) bacteremia with subsequent vancomycin treatment, and prolonged hospitalization. Leuconostoc spp. were isolated from several blood cultures and from a retracted intravascular catheter. After removal of the intravascular catheter the patient's condition improved without additional antibiotic treatment. To our knowledge, this is the first report of a patient with Leuconostoc spp. infection secondary to pulmonary non-tuberculous mycobacteriosis.