Active surveillance (AS) as a therapeutic option is already integrated as a primary treatment strategy in low risk localized prostate cancer (PCa). There is a recent interest for the search of therapeutic interventions that result in a delay in the progression of such indolent cancers. The evaluation of the possible implication of 5 ARI drugs in the reduction of the risk of progression of PCa was enacted by the results of the clinical trials PCPT (Prostate Cancer Prevention Trial) and REDUCE (Reduction by Dutasteride of Prostate Cancer Events study). The results of the REDEEM clinical trial (Reduction by Dutasteride of clinical progression events in expectant management trial)revealed a delay in PCa progression favoring Dutasteride in comparison with placebo, being advanced age and PSA Density independent predictive factors for pathologic progression. Evidences regarding the influence of 5 ARIs in the evolution of AS patients come from few studies with limited follow up. Thus, the conclusions probably are far from being consiidered as definitive.