The omentum is a rare metastatic site for prostatic adenocarcinoma. We present a case of metastatic castrate-resistant prostate cancer, with progressive omentum invasive prostate cancer identified on prostate-specific membrane antigen (PSMA) PET/CT scan. Omental biopsy revealed metastatic prostate adenocarcinoma, and cabazitaxel chemotherapy was instituted with a prostate-specific antigen biochemical response. Repeat PSMA PET/CT imaging revealed increased avidity in omental metastasis. Despite prostate-specific antigen response, PSMA PET/CT did not correlate with a therapeutic response.