Cardiac rupture (CR) is a potentialy fatal mechanical complication of ST-elevation myocardial infarction (STEMI). We aimed to determine the incidence and risk factors of CR in Chinese STEMI patients. A total of 9798 consecutive STEMI patients from four centers in China were retrospectively analyzed, among which 178 patients had CR. STEMI patients without CR were chosen as a control group. Clinical characteristics were compared between STEMI patients with CR and those without CR. The incidence of CR in STEMI patients was 1.82%, and the 30-d mortality was up to 61.2%. CR patients were significantly older, more female, and associated with a longer time from onset of pain to hospital admission than their non-CR counterparts (P<0.001). More patients with anterior myocardial infarction (82.1%) were found in the CR group, and CR patients had significantly higher heart rates than the control group ((91±19) bpm vs. (71±16) bpm;P<0.001). In multiple-adjusted models, the independent risk factors of CR were advanced age, female gender, anaemia, increased heart rate, anterior myocardial infarction, increased white blood cel (WBC) count, delayed admission, and renal dysfunction. The level of hemoglobin remained a significant deter-minant factor of CR (OR (95% CI): 0.82 (0.75–0.89);P<0.001) after adjusting for various potential confounding factors. Counts of WBC also remained a significant determinant of the CR (OR (95% CI): 1.08 (1.04–1.12);P<0.001). A number of variables were independently related to CR. This study indicated, for the first time, that both hemoglobin and WBC levels were independently correlated with occurrence of CR.