BACKGROUND: Prostate cancer (PCa) is a significant health burden within New Zealand (NZ). Survival gains from prostate cancer have created a shift in focus from survival towards quality of life (QoL) and supportive care during extended survivorship. METHOD: We launched a nation-wide cross-sectional survey and recruited three cohorts of 1000 men with prostate cancer (men diagnosed with prostate cancer within 1 year, between 1 and 3 years, and between 3 and 5 years) as well as an additional Māori men group (N = 4000 in total). The survey instruments measured quality of life, supportive care needs, and care service utilization. RESULTS: Analysis of 1075 responses revealed that Māori men experienced lower quality of life and reported greater unmet supportive care needs. Information and psychology needs were mostly reported in both Māori and non- Māori groups. Key predictors of these needs included mental health conditions, hormonal imbalances, and employment status. CONCLUSION: The study highlights significant ethnic disparities in the supportive care needs of New Zealand prostate cancer survivors (PCS), emphasizing the necessity for tailored, culturally sensitive healthcare interventions. Addressing the complex determinants of these needs is crucial for enhancing the well-being of all PCS. IMPLICATIONS FOR CANCER SURVIVORS: Actively seeking health information and mental health counselling would significantly benefit PCS by reducing unmet supportive care needs and improving overall quality of life. This approach encourages survivors to take an active role in their healthcare, potentially leading to better health outcomes and enhanced well-being.