256 Background: Data on age-specific comparisons in metastatic prostate cancer (MPC) is limited. This analysis evaluated socio-demographic and clinical characteristics among men with MPC aged <65 years versus ≥65 years. Methods: Eighty-four US men aged ≥18 years with self-reported MPC completed a cross-sectional survey in January-February 2011 which collected data on socio-demographic and clinical characteristics including treatment history and source of care. Results: Forty-nine men were aged <65 years; 35 men were ≥65 years. There were no differences (all P>0.05) between groups for marital status (80% of those <65 years and 83% of those ≥65 years were married), race/ethnicity (94% of both groups were white), education (88% of those <65 years and 77% of those ≥65 years had attended college), and annual household income (29% of those <65 years and 31% of those ≥65 years had incomes of $35,000-$54,999). Time since diagnosis differed between groups with 12%, 84%, and 4% of those aged <65 years and 3%, 69%, and 29% of those aged ≥65 years having been diagnosed <1, 1-9, and ≥10 year(s) ago, respectively (P<0.001). Respondents aged <65 years and ≥65 years reported similar experience with chemotherapy (37% in both groups had received chemotherapy), no anemia in last 4 weeks (80% and 83%, respectively), no bone fractures or spinal cord compression in last 4 weeks (90% and 94%, respectively), receiving previous radiation therapy (69% and 66%, respectively), receiving previous surgery (63% and 66%, respectively), and utilizing hormonal treatments previously or currently (86% and 90%, respectively) (all P>0.05). In addition, those <65 years versus ≥65 years did not differ regarding their self-reported source of primary care for prostate cancer (51% and 54% reported receiving their care from oncologists, respectively; 47% and 43% from urologists; 2% and 3% from family physicians/internists). Conclusions: In this study of men with MPC, those aged <65 years and those ≥65 years reported similar prostate cancer treatment utilization as well as socio-demographic and clinical characteristics with the exception of a difference in time since diagnosis. Further research in larger populations is warranted.