The concentrations of tissue plasminogen activator (t-PA) and urokinase (UK) were measured in the plasma of patients with benign or malignant ovarian and uterine tumors. Plasma levels of t-PA were higher in patients with malignant ovarian and uterine tumors than in patients with benign tumors. Plasma UK levels were, however, not different between patients with ovarian and uterine tumors (benign or malignant) and normal persons. The concentrations of t-PA and UK of tissues of uterine myoma were lower than those in normal uterine muscular layer. UK levels of tissues of endometrial and cervical cancers were significantly higher than those in normal endometrium and uterine cervix, whereas t-PA levels were not different between these tumors compared with those in normal uterine tissues.