Non-tuberculous mycobacteria are uncommon pathogens in immunocompetent individuals. We report an unusual case of pneumonia with pleural effusion caused by co-infection with two species of non-tuberculous mycobacteria in an immunocompetent man in Nigeria. The case highlights the possibility of the occurrence of a disease caused by these pathogens in an unusual host in a setting where they are rarely isolated as well as the challenges faced in diagnosis.