The present report describes the management of a 75-year-old uremic patient with delayed-onset heparin-induced thrombocytopenia and clot formation in extracorporeal circulation. The test for serum heparin-dependent platelet aggregation factor was positive and the serum platelet binding IgG (PBIgG) became elevated after the onset of heparin-induced thrombocytopenia. He required continuous exposure to heparin for hemodialysis. One gram of aspirin daily was begun to prevent clot formation in the circuit. Hemodialysis with full heparinization was achieved with no clot formation in the circuit. After aspirin ingestion, the increased level of patient's PBIgG in the presence of heparin and thrombocytopenia were restored to normal. Inhibition of platelet aggregation with aspirin allowed uneventful dialysis in a patient with heparin-induced thrombocytopenia.