OBJECTIVE: The purpose of this study was to assess the usefulness of a new platelet function analyzer in the detection of von Willebrand disease and platelet dysfunction in women with menorrhagia. STUDY DESIGN: Women with menorrhagia and control subjects were tested with a platelet function analyzer. If the results were abnormal, further testing was performed for possible von Willebrand disease or platelet dysfunction. Results were compared. RESULTS: Of the 108 women with menorrhagia, 28 had an abnormal platelet function analysis results: 7 results were suggestive of von Willebrand disease; 17 results were suggestive of platelet dysfunction, and 4 results were inconclusive. Of the 100 control subjects, 18 subjects had an abnormal platelet function analysis result: 2 results were suggestive of von Willebrand disease; 12 results were suggestive of platelet dysfunction, and 4 results were inconclusive. The prevalence of suspected von Willebrand disease was 6% among women with menorrhagia and 2% among control subjects. Among white women, the prevalence was 10% compared with 1% among control subjects. CONCLUSION: We demonstrated that the platelet function analyzer could be used to detect von Willebrand disease in women with menorrhagia.