Abstract Hemophilia is a hereditary bleeding disease characterized by functional or quantitative deficiency of factor VIIII (hemophilia A) or factor IX (hemophilia B) of coagulation. The diagnosis of hemophilia is eminently clinical; key situation offers a window of opportunity for medical staff in primary care to establish a timely and efficient diagnosis. Clinical data of the two types of hemophilia are substantially identical and differ only in relation to the grade of deficiency. This work describes a case of a newborn who presented a hematoma as a consequence of venipuncture. The patient presented prolongation in partial thromboplastin time and decreased coagulation factor VIII, confirming the diagnosis of hemophilia A. Treatment was initiated with recombinant factor VIII and the patient had a clinical improvement. This paper aims to alert the medical staff the importance of considering this disease in the differential diagnosis of hemorrhagic syndromes in the newborn, even without a family history. Appropriate treatment will generate a positive impact on the health of patients and their families, thereby reducing complications, costs of hospitalization and death.