Immune checkpoint inhibitors (ICIs) have become the cornerstone in treating many solid and hematological cancers. The ICIs, including anti-cytotoxic T lymphocyte-associated protein 4 (CTLA-4), anti-programed cell death 1 (PD-1), and anti-programed death-ligand 1 (PD-L1) monoclonal antibodies, have significantly improved the prognosis of cancer patients. Meanwhile, the incidence of hepatic or renal impairment in cancer patients is increasing. However, data about the efficacy and safety of ICIs in patients with hepatic or renal impairment are limited. In this review, we characterize and summarize the pharmacokinetics (PK) of ICIs as well as the effects of hepatic or renal function on the PK of ICIs, and provide specific recommendations for clinicians when prescribing ICIs in patients with hepatic or renal impairment.