Clinical aspects of twelve patients with benign mesenchymal lung tumours including four so-called sclerosing haemangiomas were studied. The age of the patients varied from 17 to 62 years (mean 40 years). Seven patients were female and five were male. The benign tumour was enucleated in five cases and excised by segmentectomy in one case. Three tumours were removed by lobectomy, and one by bilobectomy including bronchial resection and bronchoplasty. Two tumours (an endobronchial leiomyoma and fibroma) were removed by bronchial resection. Two patients who had previous hysterectomy for uterine leiomyomas had intraparenchymal pulmonary leiomyomas with histologically benign appearance. Although these tumours might represent metastases from uterine tumours, the follow-up of 5 and 8 years did not reveal clinically malignant features. None of the patients in this series showed tumour recurrences. Our results confirm earlier observations suggesting that the so-called sclerosing haemangioma is actually an epithelial, not a mesenchymal tumour.