Objective: Congenital pulmonary airway malformation (CPAM) is a rare developmental abnormality of the lungs. We investigated clinical characteristics of CPAM based on patient age at diagnosis. Methods: In this retrospective study, we analyzed the medical records of 51 patients diagnosed with CPAM at Pusan National University Hospital between January 2000 and December 2019. Results: We investigated 39 children and 12 adults. The mean age at the diagnosis of the patients was 15.9 ± 14.3 years. The mean ages of children and adults at the time of diagnosis of CPAM were 6.8 ± 5.8 years and 31.2 ± 10.2 years, respectively. Among the 51 patients investigated, 20 (39%) were asymptomatic and 31 (61%) showed clinical symptoms, such as dry cough, recurrent respiratory infections, and dyspnea at the time of diagnosis. Notably, clinical symptoms at diagnosis were observed in 28 children (72%) and in only 3 adults (25%) (P = 0.006), and children were more symptomatic than adults. Children with large cysts tended to be more symptomatic than those with small cysts (P < 0.001). Combined anomalies were detected in 12 patients (23%). Patients with cystic lesions in the right lower lobe of the lung showed a higher prevalence of combined anomalies (P =0.015). Surgical resection was performed in 40 patients (78%), and all patients showed good prognosis. Conclusion: This study revealed that the presence of clinical symptoms of CPAM differed between children and adults, depending on the age at diagnosis and that patients with cysts in the right lower lobe of the lungs tended to show a higher prevalence of combined anomalies. (Allergy Asthma Respir Dis 2021, 9: 21–26)