Objective: The number of men affected by incurable prostate cancer is expected to increase worldwide. Research is needed to enable men to share their experiences of unmet supportive care needs in current care delivery. We aimed to identify the most frequently reported domains of unmet supportive care needs, levels of anxiety, depression, distress, health-related quality of life, and to identify any perceived barriers to receiving supportive care. Data Sources: Men diagnosed with prostate cancer who had received a minimum of 6 months of ADT were recruited into a cross-sectional study. Participants completed standardised questionnaires; clinical and demographic data was also collected. Conclusion: Two hundred seventy-two patients were invited, and 102 participated. No statistically significant differences were found between participant scores from Australia and UK in relation to anxiety and depression, exercise, health-related quality of life, or distress scores. Perceived barriers include service delivery related to information provision and difficulties in the navigation of complex care systems. Implications for Nursing Practice: Men affected by prostate cancer receiving ADT reported unmet supportive care needs, specifically related to sexual, informational, and psychological aspects of care. Mapping future trajectories of needs and identifying men at high risk can significantly improve timely and tailored interventions.