Of patients with carcinoma of the prostate undergoing therapeutic regimes with curative intent, 15-23% will ultimately relapse and 16-35% will need some sort of salvage therapy within 5 years. Of relapsing patients, 50% will have local recurrence and 50% systemic disease with or without local recurrence. Therefore, localization of recurrent prostate cancer is critical for selecting a local or systemic therapeutic strategy. Modern fusion imaging with PET/CT and 11C/18F-choline or 11C-acetate has augmented the diagnostic imaging spectrum for assessment of relapsing prostate cancer. In 60-70% of patients with biochemical relapse, recurrent tumor can be detected and anatomically precisely localized. Detection sensitivity is probably negatively correlated with serum PSA concentration. Below a PSA level of 1 ng/ml, mean detection sensitivity is probably 50-66%. Fusion imaging with 11C-choline PET/CT and MRI possesses a high potential for early localization of recurrent prostate carcinoma.