Superficial bullae with broad bases are not suitable for resection, because the residual lung is too deformed to re-expand adequately when we resect them. Therefore, we believe superficial bullae with broad bases are suitable for ablation. It is not clear, however, whether ablated superficial bullae with broad bases remain contracted after treatment or not. We examined the morphologic changes of ablated superficial bullae with broad bases on chest computed tomographs. Ten patients with superficial bullae with broad bases that could be identified on computed tomograph underwent ablation using an electrocoagulator. These bullae were examined by chest computed tomograph preoperatively and again one, three and 12 months after surgery. There were no intra-operative complications. Postoperatively, the only complication was prolonged air leak (more than 7 days) in 1 (10%) patient. Pneumothorax after the operation presented in 1 (10%) patient. Morphologically, a disappearance of air space associated with bulla-wall thickness was observed in 9 (90%) of the 10 heat-ablated lesions and air space decreased in 1 (10%) lesion. Heat ablation proved to be effective in patients with SBBs. Lesions remained contracted for at least one year after the operation.