Objective: The aim of this study was to investigate the prognostic value of prostate-specific antigen (PSA) dynamics in patients treated with combined androgen blockade (CAB). Methods: Patients with locally advanced or metastatic prostate cancer (n = 317) received bicalutamide (50 mg once daily) plus either goserelin acetate or surgical castration for 48 weeks. Cox’s proportional hazard analysis was used to determine whether the decline of PSA following the use of this combination is predictive of a delay in progression. Results: PSA levels at weeks 4 and 12 were statistically significant prognostic markers in predicting disease progression. The PSA rate of change to week 12 was also a statistically significant prognostic marker, although the PSA rate of change at week 4 did not reach statistical significance. These results were statistically less robust than those for PSA levels. Bicalutamide plus castration was well tolerated and effective in advanced prostate cancer. Conclusion: These results suggest that PSA dynamics at weeks 4 and 12 may predict time to progression in advanced prostate cancer treated with CAB.