A 65-year-old man who had prostate cancer presented with slightly progressive prostate-specific antigen values. In this situation of biochemical relapse, prostate-specific membrane antigen (PSMA) PET/CT has proven to be superior to choline PET. The Ga-PSMA PET/CT of our patient revealed PSMA-positive tissue in the spleen. Although the localization was not typical for metastases, metastasis could not be excluded because of the intense focal tracer uptake. A supplementary MRI was performed but also failed to rule out a malignant origin. Finally, biopsy confirmed benign disease in the spleen in the form of granulomatous disease.