Background: Elevated suicide risk is established in cancer patients compared with the general population. We aim to investigate the risk of SRD among individuals diagnosed with mGU cancers. Methods: Surveillance, Epidemiology, and End Results (SEER) database (2004-2020) was queried to obtain data on suicide death in adults (>20 years of age) diagnosed with mGU cancers including bladder cancer (BC), kidney cancer (KC), and prostate cancer (PC). Standardized mortality ratios (SMRs) with 95% confidence interval (CI) were computed overall and by latency period of <1, 1-5, and >5 years (y) after the initial diagnosis of mGU cancers. SMR >1 indicated increased while <1 indicated decreased SRD. Stratification was done by age (<50y, 50-70y, >70y), race (White, Black, Asian, Native American), ethnicity (Hispanic, non-Hispanic), chemotherapy, radiotherapy, surgery, and marital. Results: This analysis included 87,357 mGU patients. In overall population, the risk of suicide-related deaths was highest <1y after diagnosis (SMR: 3.29, 95% CI: 2.47-4.29) followed by 1-5y (2.61, 2.0-3.35) and >5y (1.27, 0.61-2.34) after diagnosis. With respect to race, SRD was significantly higher in Whites (3.31, 2.46-4.36) but not in Blacks (2.58, 0.31-9.33), and Asians (2.03 (0.05-11.3). In ethnic subgroups, non-Hispanics were observed to have increased SRD (3.71, 2.77-4.86) but not Hispanics (0.83, 0.1-3.0). Patients who received chemotherapy (3.74, 2.10-6.18) or those who did not receive radiotherapy (3.66, 2.68-4.89) were more likely to die from suicide. In terms of marital status, single patients had a higher SRD (4.39, 2.94-6.30) compared to those who were married (2.54, 1.65-3.76). Detailed results are outlined in the Table. Conclusions: Patients with GU malignancies are at increased risk of SRD. Targeted and timely interventions in highest risk subgroups such as Non-Hispanic patients with a recent cancer diagnosis with no partner support, may reduce the risk of SRD in patients diagnosed with mGU cancers.