Background Shoulder pain is commonly reported after hepatic surgery; however, the factors affecting post-hepatectomy shoulder pain remain unclear. This study aimed to determine the incidence and risk factors of shoulder pain after hepatectomy. Methods This prospective cohort study recruited 218 patients who underwent hepatic resection at our hospital from June to September 2022. Data were obtained from electronic medical records and follow-up assessments on the second postoperative day. All patients denied chronic pain before surgery. In this cohort study, patients were grouped according to the appearance of shoulder pain. Demographic information and perioperative data were compared between the two groups. The relationship between shoulder pain and independent variables was assessed using univariate binary logistic regression analysis. The potential risk factors were analyzed using multivariable binary logistic regression. Results Of the 218 patients enrolled in this cohort study, 91 (41.7%) reported shoulder pain. Patients in the case group were significantly younger than those in the control group (P = 0.001). Epidural anesthesia was used more frequently in the case group (P = 0.012). Patients over 60 years of age showed a lower incidence of shoulder pain than younger patients (P = 0.028). According to multivariable binary logistic regression analysis, advanced age and epidural anesthesia were associated with risk of shoulder pain (advanced age: odds ratio [OR] [95% confidence interval (CI)]: 0.96 [0.94, 0.99], P = 0.002; epidural anesthesia: OR [95% CI]: 2.08 [1.18, 3.69], P = 0.012). Conclusions The incidence of acute shoulder pain after hepatectomy is 41.7%. The application of epidural anesthesia is an independent risk factor for shoulder pain after hepatectomy, whereas advanced age is a protective factor.