Thrombophilia represents a tendency towards excessive blood clotting and the subsequent development of venous thromboembolism (VTE). VTE is a rare condition in children that comprises both deep venous thrombosis (DVT) and pulmonary embolism (PE). This paper reports the case of a 16-year-old girl, admitted to the Pediatrics Clinic No. 1, Tîrgu Mureș, Romania, for dyspnea, chest pain and loss of consciousness. Her personal history showed that she had had two orthopedic surgical interventions in infancy, two pregnancies, one spontaneous miscarriage and a recent caesarian section at 20 weeks of gestation for premature detachment of a normally positioned placenta associated with a deceased fetus. Laboratory tests showed increased levels of D-dimers. Angio-Computed Tomography (Angio-CT) showed multiple filling defects in both pulmonary arteries, establishing the diagnosis of PE. The laboratory tests were undertaken to assist in the diagnoses of a possible thrombophilia underlined a low level of antithrombin III. Antiphospholipid syndrome was ruled out and genetic tests revealed no specific mutation. Anticoagulant therapy was initiated with unfractionated heparin and afterwards subcutaneously low molecular heparin was prescribed for three months. Later it has been changed to oral therapy with acenocoumarol. The patient was discharged in good general status with the recommendation of life-long anticoagulation therapy. Thrombophilia is a significant risk factor for PE, and it must be ruled out in all cases of repeated miscarriage.