Lymph nodes, bones, and liver are the most typical metastatic sites for prostate cancer. However, isolated liver metastasis from prostate cancer is extremely rare. Here, we report a 75-year-old man with newly diagnosed prostate adenocarcinoma, with isolated liver metastasis detected by 68Ga-PSMA (68Ga-prostate-specific membrane antigen) PET/CT. There was no sign of regional or distant metastases elsewhere. This case highlights the value of 68Ga-PSMA PET/CT in detecting a very uncommon solitary liver metastasis from prostate cancer.