The challenge of managing localized prostate cancer is to distinguish patients with clinically relevant cancers, who may benefit from radical treatment, from the remainder who do not need any intervention. Active surveillance with selective radial intervention is a management strategy that offers patients the hope of avoiding "unnecessary" treatment without detriment to their long-term survival. Here we discuss the rationale for active surveillance, and the early results. There is no consensus on the optimum active surveillance protocol, with uncertainty regarding the interpretation of PSA kinetics, repeat biopsy results and prostate imaging. In the future, it is likely that molecular markers will revolutionize our ability to select patients who will benefit from definitive treatment. In the meantime, active surveillance provides an attractive way of reducing over treatment.