To clarify the clinical feature of chronic necrotizing pulmonary aspergillosis (CNPA) complicated with non-tuberculous mycobacteriosis (NTM).Forty-one CNPA cases underlying NTM were analyzed according to their clinical backgrounds.Concerning the radiological type of prior NTM, CNPA cases were classified into two groups; 1) resembling pulmonary tuberculosis that usually shows cavitary lesion and 2) micronodule and bronchiectasis pattern, and more than half of cases (61.0%) were classified as the latter type. Average duration between prior NTM and CNPA was 1354 days. Isolation of Aspergillus spp. from sputum was 15 out of 41 (36.6%). Positive rates for Aspergillus galactomannan antigen and anti-aspergillus antibody were 58.5%, 46.3% respectively. With regard to subspecies of mycobacteria, M. avium was most frequent (82.9%). Since 6.8% of NTM cases develop CNPA within 10 years, careful observation of CNPA was required for the management of NTM.