A retrospective study was made on 22 patients who underwent surgery (28 operations) for lung metastases of colorectal origin from 1986 to 1995 at the Department of Surgery II, Padova University. The overall 5-year survival (OS) following pulmonary resection was 62% and the 5-year disease-free interval after metastasectomy (DFIM) 45%. The median survival was 23.6 months and the median DFIM 15.3 months. Univariate (Mantel Cox) and multivariate (Cox's model) analyses were used to identify any prognostic factors significant for OS and DFIM. Site and stage of primary colorectal carcinoma, number of pulmonary metastases at presentation, disease-free intervals between treatment of primary tumour and diagnosis of lung metastases (DFIP) appeared to have no influence on OS and DFIM. However, patients who underwent radical resection for metastases had a significantly longer DFIM than those who underwent 'non-radical' resections (P = 0.02), but radical resection had no significant positive effect on OS. A short DFIP, multiple and/or bilateral lesions, lung metastases occurring after liver resection with a curative aim are not contraindications to surgery in patients with pulmonary metastases from colorectal cancer, the main criterion for selection of patients being the possibility of performing 'radical' resection.