Background The aim of our study was to evaluate the long-term effects of chemotherapy and/or radiotherapy on lung function in 75 childhood Hodgkin disease (HD) and non-Hodgkin lymphoma (NHL) survivors several years after treatment. Patients and Methods. We studied 37 HD and 38 NHL survivors. These patients were divided into two groups according to the treatment protocols applied. Group I consisted of 23 patients who were treated with both chemotherapy and thoracic irradiation and Group 11 consisted of 52 patients who were treated with chemotherapy and no thoracic irradiation. A detailed history of smoking habits, respiratory symptoms, and diseases was recorded. Complete physical examinations and pulmonary function tests [PFT, including spirometry, lung volume, and diffusion capacity for carbon monoxide (DLCO)] were performed on all subjects. Results. No patients reported acute or chronic respiratory symptoms or diseases. Pulmonary function abnormality (reduced lung volume and diffusion capacity) was found in 13% of patients at a median 5 years after diagnosis. The percentage of predicted normal value of forced expiratory volume in the lst sec (FEV1), residual volume (RV), and DLCO were significantly lower in Group I than these values for Group II. There were no significant differences in PFT parameters between patients with HD and NHL (P> 0.05). it appears that the risk of reduced lung function was greater the younger the patient in therapy. Conclusion. Chemotherapy or chemo-radiotherapy-induced pulmonary sequalae in childhood may remain asymptomatic for many years.