Patients with chronic pulmonary aspergillosis (CPA) have a poor prognosis and CPA occurs in patients with various underlying diseases. Recently, the number of patients with CPA complicated by nontuberculous mycobacteria (NTM) has increased. Additionally, complications of both diseases have several problems like drug interactions. Since the impact of NTM on the outcome of CPA is not well understood, we investigated the risk factors for developing CPA and the clinical characteristics of CPA patients with or without NTM. We retrospectively investigated the medical records of NTM and CPA patients who were admitted to Nagasaki University Hospital between April 2008 and September 2013. Comorbid diseases, causative microorganisms, radiological findings, and outcomes were evaluated. During the study period, 82 and 41 patients were diagnosed as having NTM and CPA, respectively. Nine patients were coinfected with NTM and CPA, and cavitary type NTM and steroid usage were independent risk factors of development of CPA. Mortality rates in the coinfection group were significantly higher than those of the NTM without CPA group (P = .003, log-rank test). The rate of treatment initiation in the co-infection group (33.3%) was significantly lower than in the CPA without NTM group (84.4%) (P = .006). However, there were no significant differences in cumulative survival rate between both groups (P = .760, log-rank test). Cavity formation and steroid usage were the independent risk factors for NTM patients to develop CPA within long observation period, and development of CPA made outcomes poor. It is important to diagnose the development of CPA early and initiate treatment for CPA.