Assessment of outcome following radical treatment for stages T1 to T2 prostate cancer has become more sensitive and rapid with the use of serum prostate specific antigen (PSA) in routine followup. PSA has identified substantially more failure following all radical therapies than was previously detected in series using clinical end points. Furthermore, it has also allowed a better assessment of the biological potential of histologically evident residual disease, that is a positive surgical margin after prostatectomy or positive repeat biopsy 2 years after radiation. Both situations are associated with subsequent biochemical failure in the majority of patients. The stages T1 to T2 cancer group is extremely heterogenous. In the few series with PSA followup that have evaluated long-term (greater than a decade) outcome for this group some report cure rates well below 40% for surgery and radiation. When comparing the results of any radical treatment series (surgery versus surgery and radiation versus radiation, as well as radiation versus surgery) selection may have a crucial role in predicting outcome. Surgical series tend to contain more patients with stages T1 to T2a tumors of low grade who have low initial PSA values and are known to have negative nodes. These patients, when treated with radical radiation, also have a favorable prognosis. It is hoped that the introduction of screening programs will improve outcome through earlier disease detection.