Objective: This study aims to investigate the presence of acquired and hereditary coagulation in adolescent girls presenting with increased menstrual bleeding. Method: The study consisted of 63 adolescent female patients (15.4±1.5 years) who applied to the pediatric clinic of our hospital due to increased menstrual bleeding, did not have any acute or chronic disease, did not use any medication in the last 14 days, and were of the same age and gender as the study group. 74 healthy adolescents were taken as the healthy control group (15.5±1.5 years). Platelet count, all basal and advanced coagulation tests, platelet aggregation, and secretion tests were studied for each case included in the study. Results: When basal and advanced coagulation tests, platelet aggregation, and secretion tests were examined, no significant difference was found between the study and the healthy control group. On the other hand, in our study group with heavy menstrual bleeding, 4 (6.3%) patients were found to have impaired hemostasis (2 patients with type 1 von Willebrand disease, one patient with immune thrombocytopenic purpura, and one patient with mild factor VIII deficiency). Conclusion: Various hemostasis disorders, especially von Willebrand disease, could be detected in the group with heavy menstrual bleeding.