BACKGROUND: Colorectal cancer (CRC) is the third most prevalent form of cancer worldwide. Among patients with CRC, colorectal liver metastasis (CRLM) is the foremost direct contributor to mortality. In recent years, immunotherapy has swiftly risen to prominence as a vital approach for treating a range of solid tumors, including CRC. We present a unique case of a patient suffering from CRLM, with the goal of offering an insightful example and relevant references for the treatment of CRLM. CASE SUMMARY: We report a patient who experienced liver metastasis after undergoing successful surgical removal of CRC, with the postoperative pathological stage identified as pT4N2aM0. The patient has been receiving a combination treatment of Western and Traditional Chinese Medicine. Regular assessments of the patient's condition have been conducted, encompassing evaluations of serum carcinoembryonic antigen levels, carbohydrate antigen 199, and observations of the tongue complexion and its coating. The patient achieved clinical remission after anti-programmed death-1 immunotherapy when various systemic therapies failed. Since the diagnosis of CRLM, the patient has survived for more than 6 years, surpassing the expected survival time for those with advanced CRC. CONCLUSION: This case illustrates the considerable promise of anti-programmed death-1 immunotherapy in managing CRLM, especially in scenarios of drug resistance and disease progression.