Objective Chronic pulmonary aspergillosis (CPA) is an important complication of nontuberculous mycobacterial pulmonary disease (NTM-PD). However, its diagnosis is challenging, as both CPA and NTM-PD present as chronic cavitary disease. The present study evaluated the impact of CPA on the survival of patients with NTM-PD and revealed the key computed tomography findings for a prompt diagnosis. Methods We retrospectively reviewed patients newly diagnosed with NTM-PD in Tenri Hospital (Tenri City, Nara Prefecture, Japan) between January 2009 and March 2018; the patients were followed up until May 2021. Clinical and radiological characteristics were assessed, and patients with CPA were identified. Results A total of 611 patients were diagnosed with NTM-PD. Among them, 38 (6.2%), 102 (17%), and 471 (77%) patients were diagnosed with NTM-PD with CPA, cavitary NTM-PD without CPA, and non-cavitary NTM-PD without CPA, respectively. The 5-year survival rate of the NTM-PD with CPA group (42.8%; 95% confidence interval: 28.7-64.0%) was lower than that of the cavitary NTM-PD without CPA group (74.4%; 95% confidence interval: 65.4-84.6%). A multivariate analysis revealed that fungal balls and cavities with adjacent extrapleural fat were significant predictive factors for NTM-PD with CPA. Conclusion NTM-PD with CPA patients exhibited a worse prognosis than cavitary NTM-PD without CPA patients. Therefore, an unerring diagnosis of CPA is essential for managing patients with NTM-PD. Computed tomography findings, such as fungal balls and cavities with adjacent extrapleural fat, may be valuable diagnostic clues when CPA is suspected in patients with NTM-PD.