68Ga–prostate-specific membrane antigen (PSMA) PET/CT is a rapidly evolving diagnostic technique to image prostate cancer. In contrast to the name PSMA, various tissues show 68Ga-PSMA uptake in PET/CT imaging. We present a case of a 68-year-old man with prostate cancer who underwent Ga-PSMA PET/CT. Along with metastatic lymph nodes, multiple nodular lesions within the peritoneal spaces of all 4 quadrants of the abdomen showed high PSMA expression. Because of a history of splenic rupture, a 99mTc-labeled heat-denatured erythrocyte scintigraphy and SPECT were performed. Peritoneal lesions showed high uptake, confirming widespread peritoneal splenosis.