Leiomyomas and leiomyosarcomas of the gastro-intestinal tract are quite uncommon tumours. Clinical findings are aspecific: abdominal pain and gastrointestinal bleeding. Diagnosis is made by X-ray with contrast, endoscopy and CT-scan. Although biopsies taken during endoscopy are considered to be useless, our experiences showed an accurate diagnosis with biopsies. Surgery is the only treatment. The aim is to reduce the mass of tumour as much as possible; second look operations with careful debulking enhances the survival in case of recidive. Resection of lymph-nodes is useless. Radiotherapy nor chemotherapy are proven to be useful. The grade of malignity determines the prognosis. The liver and the abdominal cavity are the predilected localisation for metastasis. Metastasis in lymph-nodes is uncommon. Five year survival is about 50%.