Objective To investigate the positive rate of heparin/platelet factor 4 (H/PF4) antibody in maintenance hemodialysis (MHD) patients, and to explore its clinical significance. Methods Fifty-four MHD patients treated in the Department of Nephrology of Changzheng Hospital of Naval Medical University (Second Military Medical University) were selected. The dialysis duration (unfractionated heparin/low-molecular-weight heparin) of all patients was more than 3 months, with no infections or other active diseases. Serum samples were collected from the MHD patients before dialysis, and IgG H/PF4 antibody was detected by particle immunofiltration assay. The general condition, hemoglobin level, platelet count, anticoagulant method (unfractionated heparin/low-molecular-weight heparin), anticoagulant dosage, and dialysis mode (conventional hemodialysis/nocturnal extended hemodialysis) were compared between the H/PF4 antibody-positive group and H/PF4 antibody-negative group. After 3 years' follow-up, the change of platelets, the incidence of vascular access thrombosis, cardio-cerebral vascular events, hospitalization rates and mortality were compared between the two groups. Results The positive rate of H/PF4 antibody was 63.0% (34/54) in MHD patients. There were no significant differences in gender, age, dialysis age, hemoglobin level or platelet count between the H/PF4 antibody-positive group and H/PF4 antibody-negative group (P>0.05). The positive H/PF4 antibody was not correlated with primary kidney disease, anticoagulant method, anticoagulant dosage, or dialysis mode (all P>0.05). After 3 years' follow-up, there were no significant differences in the change of platelet, the incidence of vascular access thrombosis (14.7%[5/34] vs 25.0%[5/20]), cardiovascular events, cerebrovascular events, hospitalization rates, or mortality between the two groups (all P>0.05). Conclusion The positive rate of H/PF4 antibody is high in MHD patients. The production of H/PF4 antibody is not related to the heparin type, heparin dosage, or dialysis mode. The positive H/PF4 antibody has no significant effect on platelet counts or adverse events, including thrombosis and cardiovascular events.