Two patients with skin necrosis in the injection points after subcutaneous prophylactic porcine calcium heparin administration are reported. In addition, both patients had thrombopenia, deep venous thrombosis and pulmonary thromboembolism. The review of similar cases suggests that skin necrosis is another feature of the thrombopenia and multiple vascular thrombosis syndrome associated with heparin administration. Data from the literature suggest that there is a common immunologically-mediated pathogenetic mechanism responsible for these phenomena through the production of platelet aggregates and immune reaction in endothelial cells. Paradoxically, the continuation of therapy with intravenous sodium heparin was not followed in our patients by new complications despite the theoretical risk.