Objective To investigate the correlation between perioperative neuropeptide Y (NPY) levels and adverse cardio⁃ vascular events (ACVE). Methods One hundred and two patients, American Society of Anesthesiologists (ASA) physical status Ⅰ or Ⅱ, aged 43‒82 y, undergoing hip or knee replacement under intrathecal anesthesia, were enrolled and assigned into two groups: dia⁃ betic group (DM, n=49) and non⁃diabetic group (NDM, n=53), according to whether the patients carried type 2 DM. The two groups of patients were further assigned into four subgroups: DM group was divided into cardiovascular disease (CVD) group (DM⁃CVD) and non⁃CVD group (DM⁃NCVD), non⁃DM group was also divided into two groups: the subgroup with cardiovascular disease named NDM⁃CVD while non⁃DM group without cardiovascular disease named NDM⁃NCVD group. Intraoperative cardiovascular events were recorded and analyzed. Serum concentrations of NPY were determined by enzyme⁃linked immunosorbent assay (ELISA) at the time point: 30 min before operation, the end of surgery and 24 h after operation. The incidence of perioperative ACVE was recorded and ana⁃ lyzed, and the correlation between the concentration of serum NPY and the incidence of ACVE was analyzed by Spearsman correlation analysis. Results The perioperative total ACVE incidence in the DM group was higher than that in the NDM group (65.30% vs. 30.19%, P<0.05); compared with the DM⁃NCVD subgroup, the DM⁃CVD subgroup had a high incidence of ACVE during the periopera⁃ tive period (44.44% vs. 77.42%, P<0.05); compared with NDM⁃NCVD subgroup, the NDM⁃CVD subgroup had a high incidence of ACVE during the perioperative period (17.86% vs. 44.00%, P<0.05). Compared with the NDM group, the serum NPY at each time point in the DM group was significantly increased (P<0.05); compared with the preoperative level in the same group, the serum NPY after the operation was significantly increased in the DM group (P<0.05); compared with patients without ACVE, the serum NPY levels of pa⁃tients with ACVE were significantly increased at each time point (P<0.05). The serum NPY levels of patients in the DM group and NDM group were correlated with ACVE at each time point (P<0.05). Conclusions The incidence of intraoperative adverse cardio⁃ vascular events was closely associated with higher level of serum NPY.