Active surveillance is now an accepted management strategy for men with low-risk localized prostate cancer, in recognition of the knowledge that the majority of men with such cancers are likely to die from other causes. The most obvious benefit of active surveillance is the reduction of morbidity associated with surgery by delaying or avoiding radical gland therapy. Other advantages include lower overall costs to the health-care system and potentially a better quality of life. These advantages should be balanced against the risks of delayed therapy, the most considerable of which being development of more-aggressive disease. Appropriate selection criteria and the definition of triggers for intervention with radical therapy are critical components of an active surveillance protocol. The ability to accurately identify and cure the men whose cancers will progress using clinical, biopsy and imaging data is yet to be resolved, as is the psychological burden of living with an untreated cancer. The benefit of 5α-reductase inhibitors as secondary chemoprevention in men on active surveillance is a new avenue of research. Focal therapy, which has the similar aim of reducing morbidity while maintaining oncological control, is an emerging competitor for active surveillance. Nevertheless, active surveillance is an appealing management option for selected men with prostate cancer.