Excessive menstrual bleeding is a common clinical problem in women of reproductive age. Hereditary bleeding disorders, such as von Willebrand disease, may be one of the causes of menorrhagia. The aim of our study was to assess the frequency of von Willebrand disease and other hemostatic defects in women with unexplained menorrhagia and without uterine pathology. Sixty-five women (mean age 31 +/- 8.7, range 18-48 years) presenting with menorrhagia were screened. An inherited bleeding disorder was diagnosed 9 (13.8%) patients; the disorders were von Willebrand disease of mild severity (type 1) in 8 cases (12.3%) and a platelet dysfunction (storage pool disease) in 1. The frequency of bleeding symptoms was higher in patients with an inherited hemostatic defect than in women without bleeding disorder. The results of this study underscore the need for hemostatic evaluation in women with excessive menstrual bleeding and without obvious pelvic abnormality.