Importance:Prostate cancer is the most common cancer diagnosis made in men with more than 160 000 new cases each year in the United States. Although it often has an indolent course, prostate cancer remains the third-leading cause of cancer death in men. Observations:When prostate cancer is suspected, tissue biopsy remains the standard of care for diagnosis. However, the identification and characterization of the disease have become increasingly precise through improved risk stratification and advances in magnetic resonance and functional imaging, as well as from the emergence of biomarkers. Multiple management options now exist for men diagnosed with prostate cancer. Active surveillance (the serial monitoring for disease progression with the intent to cure) appears to be safe and has become the preferred approach for men with less-aggressive prostate cancer, particularly those with a prostate-specific antigen level of less than 10 ng/mL and Gleason score 3 + 3 tumors. Surgery and radiation continue to be curative treatments for localized disease but have adverse effects such as urinary symptoms and sexual dysfunction that can negatively affect quality of life. For metastatic disease, chemotherapy as initial treatment now appears to extend survival compared with androgen deprivation therapy alone. New vaccines, hormonal therapeutics, and bone-targeting agents have demonstrated efficacy in men with metastatic prostate cancer resistant to traditional hormonal therapy. Conclusions and Relevance:Advances in the diagnosis and treatment of prostate cancer have improved the ability to stratify patients by risk and allowed clinicians to recommend therapy based on cancer prognosis and patient preference. Initial treatment with chemotherapy can improve survival compared with androgen deprivation therapy. Abiraterone, enzalutamide, and other agents can improve outcomes in men with metastatic prostate cancer resistant to traditional hormonal therapy.