The occurrence of cancer in a pregnant woman is a relatively infrequent event. The influence of pregnancy on the initiation, promotion and development of sarcomas is yet unclear. The medical approach is strongly influenced by the type and site of the primary tumor, its growth rate and associated symptoms, and by the need to treat the woman while minimizing fetal toxicity. The medical files of seven pregnant women in whom sarcomas were diagnosed during gestation or 3-4 months after delivery were reviewed. Three had bone sarcomas, and four had soft tissue sarcomas. In five cases there were various reasons for the delayed diagnosis and treatment, including lack of any signs or symptoms during gestation, clinical misdiagnosis, religious attitude and refusal of the patients. Ancillary tests such as magnetic resonance imaging (MRI) and ultrasound, and biopsy, are safe during gestation. Adriamycin, ifosfamide and granisetron were administered in one case during the third trimester, without remarkable toxicity. Whenever a pregnant woman is diagnosed as having a malignant tumor, serious medical, ethical, emotional, religious and philosophical dilemmas arise. The mother's well-being and the risk to the fetus by introducing early diagnostic tests and treatment should be weighed against the risk to the mother and the well- being of the fetus in carrying on an uninterrupted gestation.