Abstract. Six cases of pregnancy associated with sarcoma are presented. Among these six cases is one patient with vulvar sarcoma which was diagnosed during the 34th week of pregnancy. The literature was reviewed with reference to the effect which pregnancy may have on the growth of malignant tumors. Most authors believe that pregnancy has no deleterious effect on the course of cancer, however, this is not well supported through adequate data. Several reports to the contrary contain evidence that pregnancy may have a deleterious effect on the course of cancer. These discrepancies could be explained on the basis of differences in the natural history and biological behavior of different malignant tumors in relation to the pregnancy.