A 40-year-old woman with severe anorexia nervosa was found to have a bilateral pulmonary infection with rare atypical mycobacterium Mycobacterium szulgai. Of note, she had no preexisting structural lung disease or history of tuberculosis, smoking, or HIV. Current data suggest that both impaired cell-mediated immunity and altered respiratory mechanics are risk factors for mycobacterial infection in patients with anorexia nervosa.