Roentgenographically occult lung cancers (ROLCs) are rare but are usually curable if they are properly diagnosed and treated. Between 1977 and 2000, we treated 51 patients with early hilar lung cancer (as defined by the Japan Lung Cancer Society) of ROLC form. If the occurrence of cancer is confined to segmental bronchi, we preserve the lung tissue as far as possible by using a sleeve segmentectomy. Eight of the 51 patients underwent sleeve segmentectomy. All 8 of these patients were men who were heavy smokers and had a mean age of 64.9 years (range, 59-74 years). The cancerous locations were R-B6 in 4 patients, L-B(1+2+3) in 2 patients, L-B(4+5) in 1 patient, and L-B6 in 1 patient. Two patients had double cancers (synchronous in one case and metachronous in the other). All 8 of the patients had squamous cell carcinoma, 3 of whose lesions were carcinoma in situ. The segments resected were R-S(6) in 3 patients, L-S(1+2+3) in 2 patients, L-S(4+5) in 1 patient, L-S(6) in 1 patient, and R-S6 combined with the middle lobe in 1 patient. There were no cases of morbidity or mortality. However, 1 patient who had undergone a left lower lobectomy for synchronous advanced squamous cell carcinoma 4 months before R-S(6) sleeve segmentectomy for contralateral early hilar lung cancer died of recurrence in the mediastinal lymph nodes 63 months after the first operation. Two patients died of other causes: one of pneumonia 61 months after L-S(4+5) sleeve segmentectomy and the other of myelopathy 36 months after L-S(1+2+3) sleeve segmentectomy. The remaining 5 patients are alive and well 178, 121, 109, 94, and 14 months after surgery. Sleeve segmentectomy is a curative operation for early stage squamous cell carcinoma of the segmental bronchus that preserves pulmonary function and should be used to treat patients carefully selected for the correct indications.