Objectives: To examine the treatment outcomes of men who would have been eligible for active surveillance (AS) but underwent immediate radical retropubic prostatectomy (RRP). AS protocols are designed to spare the potential morbidity of treatment to patients with low-risk prostate cancer (PCa).Methods: From a prospective RRP database, we evaluated the tumor features and treatment outcomes for men who would have met 1 of 3 published AS criteria: (1) clinically localized disease, Gleason < or = 7, and no significant comorbidities (Patel et al, J Urol. 2004;171:1520-1524) (2) T1b-T2b N0M0 disease, Gleason < or = 7, and prostate-specific antigen < or = 15 ng/mL (Choo R et al. J Urol. 2002;167:1664-1669), or (3) T1c PCa (Mohler JL et al. World J Urol. 1997;15:364-368.).Results: 3959, 3536, and 2330 RRP patients, respectively, would have met these AS criteria. At surgery, 3%-4% had a Gleason score of 8-10, 16%-19% had positive surgical margins, 15%-18% had extracapsular tumor extension, 3%-5% had seminal vesicle invasion, and 0.4%-1% had lymph node metastasis. The 5-year progression-free survival rate ranged from 84%-89%. Metastasis occurred in 0.1%-1.2%, and 0.1%-0.9% died of PCa. On multivariate analysis, Gleason score > 6 was the strongest predictor of biochemical progression.Conclusions: A substantial proportion of men who might have been considered potential AS candidates had aggressive tumor features at RRP and/or progression. Biopsy Gleason score > 6 was the strongest predictor of adverse outcomes, highlighting the importance of limiting AS to patients with Gleason < or = 6. Overall, the accurate identification of patients with truly indolent PCa at the time of diagnosis remains challenging.