This paper reports our results with sublobar resections for stage I non small cell lung cancer. Sixty-one cases of wedge or segmental resection were compared with 517 standard resections (411 lobectomies and 106 pneumonectomies), performed during the years 1971-88. Operative mortality was 0% in the limited resection group and 4% (19/517) in the standard resection group; cancer recurrence was detected in 36% of both groups; actuarial survival at 5 years was 55% versus 48% overall. In 28 patients with pre-existing cardiac or pulmonary co-morbidity, limited resection yielded a similar 5-year survival than standard resection (53% vs 49%) with no perioperative deaths (0 vs 6%). Our data support the experience of other authors on conservative management of stage I lung cancer. Particularly in patients with concomitant cardio-pulmonary disease, previous cancer or small peripheral tumors, limited resection combined with adequate nodal staging may be as effective as standard lobar resection with respect to long term survival.