Background This meta-analysis examined the risk of hepatotoxicity in patients with solid tumors who received a PD-1/PD-L1 inhibitor alone, a PD-1/PD-L1 inhibitor plus chemotherapy, or chemotherapy alone. Methods Potentially eligible studies were identified by searches of Embase and PubMed. All included studies were randomized controlled trials (RCTs) that examined patients with solid tumors who received a PD-1/PD-L1 inhibitor and/or chemotherapy. Results We included 20 clinical trials (11,634 patients). Thirteen trials compared PD-1/PD-L1 inhibitor monotherapy with chemotherapy. These two groups had similar risk for elevated markers of hepatotoxicity (based on analysis of all marker grades and high marker grades), although the PD-1/PD-L1 inhibitor group had an elevated relative risk (RR) of elevated aspartate aminotransferase (AST; RR = 2.13, 95% CI = 1.04 to 4.36, P = 0.04) when considering high grades alone; however, this disparity was not significant for comparisons of the pembrolizumab and nivolumab subgroups with the chemotherapy group. Compared with chemotherapy, PD-1/PD-L1 inhibitors increased the risk of all-grade hepatitis (RR = 5.85, 95% CI = 1.85 to 18.46, P < 0.01), and high-grade hepatitis (RR = 5.66, 95% CI = 1.58 to 20.27, P < 0.01). Seven other studies compared PD-1/PD-L1 inhibitor plus chemotherapy with chemotherapy alone. The combined treatment led to a higher risk for all-grade hepatitis (RR = 2.14, 95% CI = 1.29 to 3.55, P < 0.01) and high-grade hepatitis (RR = 5.24, 95%CI = 1.89 to 14.52, P < 0.01), but these groups had similar risk for all-grade and high-grade elevated markers of hepatotoxicity. Conclusions Relative to chemotherapy alone, PD-1/PD-L1 inhibitors with or without chemotherapy increased the risk of all-grade and high-grade hepatitis, but generally did not increase the risk of elevated blood markers of hepatotoxicity.