PURPOSE OF REVIEW: Prostate cancer is a complex and biologically heterogeneous disease that is not adequately assessed with conventional imaging alone. Molecular imaging with positron emission tomography (PET) is poised to fill this unmet need through noninvasive probing of the multiple molecular and cellular processes that are active in prostate cancer patients. RECENT FINDINGS: Several PET tracers are active in early-stage and late-stage prostate cancer in humans. F18-Fluorodeoxyglucose (FDG), C11/F18-choline and sodium F18-fluoride have been studied most extensively. There is a growing body of literature supporting the utility of choline in early-stage prostate cancer. FDG and sodium F18-fluoride are more valuable in advanced disease, especially for assessing bone metastases, the prevalent form of metastases in this patient population. F18-fluorodihydrotestosterone is active in castrate disease and is emerging as a valuable pharmacodynamic marker in the development of novel androgen receptor-targeted therapies. Prostate-specific membrane antigen PET tracers are in the early stages of clinical development. SUMMARY: Multiple PET tracers are currently available to aid in the detection and management of prostate cancer across the clinical spectrum of the disease. Prospective, rigorously controlled, clinical imaging trials are needed to establish the optimal role of PET in prostate cancer.