The case-record describes a 23-year-old female patient hospitalized on account of phlebothrombosis of the right upper extremity, associated with protein C deficiency and the use of hormonal contraception. The patient was treated with heparin and subsequently warfarin treatment. During the check-up examination by duplex sonography one month after discharge the thrombus was fully recanalized. The authors discuss the causes, diagnosis and treatment of thromboses of the upper extremities.