Primary hepatic neuroendocrine carcinoma is a rare disease and is short of specific clinical and imaging features. The pathological diagnosis is the gold standard. In this case, the patient presented with rectal adenocarcinoma with multiple liver lesions, which were thought as metastases from rectal cancer. Under the treatment, the primary rectal tumor responded well to the chemotherapy, while the liver lesions progressed rapidly. A biopsy to the liver was then performed, and the pathologic diagnosis revealed primary hepatic neuroendocrine carcinoma. Because of abnormal liver function and poor performance status, the patient was not tolerable for further treatment. This case indicated that we should be aware of the posibility of multiple cancers in clinical work.