We retrospectively reviewed 110 consecutive patients with interstitial lung diseases (ILDs) who underwent surgical lung biopsy over 13 years from 1989-2002. Surgical procedures, medical records, surgical complications and outcome including post-operative exacerbation of ILDs were assessed in order to clarify the safety and efficacy of surgical lung biopsy. Forty-one patients underwent open lung biopsy (OLB), while 69 patients received videothoracoscopic lung biopsy (VTLB). There was no significant difference in patient characteristics, pulmonary function, arterial oxygen pressure and therapy prior to surgery between the two groups. The mean number of biopsy specimens was 2.5. Left side was selected as the site of biopsy in 70 cases. Duration of surgery was not significantly different between 2 groups. Bleeding during operation was less in the VTLB group than in the OLB group, although the mean bleeding amount was only 16.5mL. The duration of thoracic drainage and length of hospital stay were shorter in the VTLB group. The overall rate of surgical complications was 10.9%, with no difference between the two groups. The overall 30-day post-SLB mortality was 6.4% and majority of these had a very poor prognosis pathologically. The diagnostic yield of all 110 cases was 98.2%. SLB is a relatively safe and efficient diagnostic method in the diagnosis of ILDs.