Chlorpromazine (CPZ), a first-generation antipsychotic, is widely used in treating schizophrenia and other psychiatric disorders. However, CPZ is also associated with an increased likelihood of sudden cardiac death, and the underlying mechanisms remain unclear. In our study, we aimed to determine the CPZ-induced changes in some members of the heat shock protein family in rat hearts and further explore the possible mechanisms of CPZ-induced cardiotoxicity. Twenty-four Sprague Dawley rats were randomly divided into three groups (n = 8 per group): control, low dose (33.216 mg/kg) and high dose (94.211 mg/kg). CPZ administration induced hypothermia in rats. Pathological changes, including ischaemia and hypoxia, were observed in rat hearts. Furthermore, the serum levels of cardiac Troponin T (c-TN-T) and brain natriuretic peptide (BNP) were elevated in the CPZ-exposed groups. Meanwhile, the protein and gene expression of HSP70, HSP60, HSP27 and HSP10 significantly differed between the CPZ-exposed and control groups. We conclude that acute CPZ exposure could lead to myocardial injury in rats, in which HSPs might play a crucial role. Further investigations are required to elucidate the underlying mechanisms.