To assess the patient and cancer characteristics as well as outcomes of a large cohort of Australian men who chose active surveillance (AS) as initial management of their low-risk prostate cancer. PATIENTS AND METHODS: Men treated by one surgeon who had chosen AS as the primary management for prostate cancer were identified from the records. The patient and cancer data recorded included: patient age, prostate-specific antigen (PSA) concentration at diagnosis, mode of prostate cancer detection. For prostate cancer diagnosed at prostate biopsy, data were collected for the number of cores taken as well as positive core number, cancer burden, and Gleason grade. Survival analysis was used to determine the duration of AS. RESULTS: In all, 154 men with low-risk prostate cancer with a median (range) age 63.0 (36-81) years and a mean (range) PSA concentration of 6.5 (0.3-22) ng/mL underwent AS. The median (range) duration of AS was 1.9 (0.1-16.6) years. AS was ceased in 29 patients (19 ) after a mean (range) of 2.4 (0.2-7.9) years. Of these, 26 were upstaged, one chose curative treatment despite stable disease, and two died from disease not related to prostate cancer. Actuarial analysis on the probability of still being on AS after 5 years was 61.9 (95 confidence interval [CI] 46.2-74.2 ) and after 10 years was 45.0 (95 CI 21.3-66.2 ). While the period of follow-up is short, there were no biochemical recurrences in men who underwent curative treatment and no deaths from prostate cancer. CONCLUSION: AS is an acceptable mode of initial treatment in Australian men with low-risk prostate cancer.