The optimal management of menorrhagia among women with abnormal laboratory haemostasis is uncertain. In a crossover study, 116 women with menorrhagia [pictorial blood assessment chart (PBAC) score >100], negative gynaecological evaluation and abnormal laboratory haemostasis were randomly assigned to either intranasal desmopressin (IN-DDAVP) or tranexamic acid (TA) therapy for two menstrual cycles. The subjects then crossed over to the second study drug for two additional cycles. Menstrual blood loss (MBL) was measured by PBAC scores at baseline and after each menstrual cycle. Quality of life (QOL) was assessed with four validated instruments. There was a statistically significant decrease in PBAC scores for both treatments. On average, the estimated decrease in the PBAC from baseline was -64.1 [95% confidence interval (CI) = -88.0, -40.3] for IN-DDAVP and -105.7 (95% CI = -130.5, -81.0) for TA. The decrease in PBAC score was greater for TA than IN-DDAVP (a difference of 41.6, P-value = 0.0002, 95% CI = 19.6, 63.6). The test for treatment-type effect was significant (P < 0.0001) suggesting a greater reduction in PBAC score with TA. Use of both IN-DDAVP and TA improved QOL by all four instruments. We conclude that both medications reduced MBL and improved QOL among females with menorrhagia and abnormal laboratory haemostasis, but TA proved more effective.