Introduction: We sought to compare the rate of return of testosterone levels and sexual function in men with prostate cancer receiving longer acting, 3-month preparation of luteinizing hormone-releasing hormone agonist (L-LHRH-A) versus shorter acting, 1-month preparation of luteinizing hormone-releasing hormone agonist (S-LHRH-A). Methods and Materials: Men with low to intermediate risk localized prostate cancer were randomized to either L-LHRH-A (2-3 month duration LHRH-A) or S-LHRH-A (6-1 month duration LHRH-A) of androgen suppression therapy (AST) and prostate brachytherapy using iodine-125 radioisotopes. Serum total testosterone levels and PSA were recorded every 2 months for 2 years. Results: A planned target sample size of 100 was not achieved due to insufficient accrual. A total of 55 patients were randomized and 46 were used for analysis. The median time to recovery of testosterone to baseline levels (calculated from end of AST) was 8 and 4 months in the L-LHRH-A and S-LHRH-A arms, respectively (p = 0.268). The median time to testosterone recovery to lower limit of reference range was 4 and 2 months respectively (p = 0.087). Interpretation: This randomized study, which failed to reach accrual target, showed a trend towards more rapid recovery of testosterone levels using shorter acting LHRH-A. Another randomized study would be required to validate these findings. Currently, there is insufficient evidence to recommend the use of shorter acting LHRH-A as a means of providing more rapid recovery of testosterone levels.