Background: While population-based estimates of advanced prostate cancer survivors are lacking, an estimated 180,000 men in the US are living with metastatic prostate cancer. Their survivorship experience is distinct from localized patients as they suffer quality of life detriments both due to the severity of disease and its therapies. We examined quality-of-life indictors among men in the IRONMAN global registry of advanced prostate cancer. Methods: IRONMAN (International Registry of Men with Advanced Prostate Cancer) is a population-based prospective study of men with newly diagnosed advanced, metastatic hormone-sensitive (mHSPC) and castration-resistant prostate cancer (CRPC) enrolled from 16 countries. We report data from first 1865 men enrolled, 1567 who completed a baseline Patient Reported Outcome Measure (PROM) in the US (N=581), Canada (N=245), Spain (N=166), UK (N=204), Australia (N=126), Switzerland (N=88), Sweden (N=70), Ireland (N=46), and Brazil (N=41). PROMs are collected at baseline and every three months using electronic (90%) or paper versions of validated questionnaires. Results: The cohort includes 1,128 men with mHSPC and 737 with CRPC. Based on self-report, 9% of men overall (18% in the US) are Black and 83% are white (78% in the US). Sleep problems were common among men at enrollment, with 59% of men reporting problems with insomnia. The prevalence was similarly high among men with mHSPC or CRPC disease. Ten percent of men reported that pain substantially interfered with daily activities, and 24% reported pain had some effect. Physical functioning was high among both mHSPC (median 93.3, 80-100) and CRPC (median 86.7, 73.3-100) patients based on EORTC QLQ-30. Global health status was similar between the two groups (median 75, 58.3 - 83.3). More than 25% of men reported some cognitive impairment at baseline. Financial difficulties due to the disease and treatment were quite high, ranging from 12% in Sweden, 16% in Canada and Spain, 34% in the US, and 46% in Brazil. Conclusions: Men with advanced prostate cancer experience a range of quality of life detriments which impair overall health. While at baseline, many of these measures were similar among men with mHSPC and CRPC, we will continue to monitor these over time to examine changes in quality of life associated with disease progression and treatments. A longer-term goal is to identify opportunities for intervention to improve quality of life and potentially improve survival. Clinical trial information: NCT03151629.