IMPORTANCE: Cardiovascular disease is a leading cause of mortality in patients with prostate cancer, and androgen deprivation therapy (ADT) may worsen cardiovascular risk. Adherence to guideline-recommended assessment and management of cardiovascular risk factors (CVRFs) in patients initiating ADT is unknown. OBJECTIVE: To describe CVRF assessment and management in men with prostate cancer initiating ADT and overall. DESIGN, SETTING, AND PARTICIPANTS: A cross-sectional analysis of 90 494 men treated within the US Veterans Health Administration diagnosed with prostate cancer between January 1, 2010, and December 31, 2017, was conducted. Participants included men with a history of atherosclerotic cardiovascular disease (ASCVD), and treatment with ADT within 1 year of diagnosis. Data analysis was conducted from September 10, 2019, to July 1, 2020. MAIN OUTCOMES AND MEASURES: Rates of comprehensive CVRF assessment, uncontrolled CVRFs, and untreated CVRFs. Comprehensive CVRF assessment was defined as recorded measures for blood pressure, cholesterol, and glucose levels; CVRF control as blood pressure lower than 140/90 mm Hg, low-density lipoprotein cholesterol 130 mg/dL, and hemoglobin A1c less than 7%; and CVRF treatment as receipt of cardiac risk-reducing medications. Multivariable risk difference regression assessed the association between ASCVD and initiation of ADT and these outcomes. RESULTS: Of 90 494 veterans, median age was 66 years (interquartile range, 62-70 years); and 22 700 men (25.1%) received ADT. Overall, 68.1% (95% CI, 67.8%-68.3%) of the men received comprehensive CVRF assessment; 54.1% (95% CI. 53.7%-54.4%) of those assessed had uncontrolled CVRFs, and 29.6% (95% CI, 29.2%-30.0%) of those with uncontrolled CVRFs were not receiving corresponding cardiac risk-reducing medication. Compared with the reference group of patients without ASCVD not receiving ADT, patients with ASCVD not receiving ADT had a 10.4% (95% CI, 9.5%-11.3%) higher probability of comprehensive CVRF assessment, 4.0% (95% CI, 2.9%-5.1%) lower risk of uncontrolled CVRFs, and 22.2% (95% CI, 21.1%-23.3%) lower risk of untreated CVRFs. Similar differences were observed in patients with ASCVD receiving ADT. In contrast, patients without ASCVD receiving ADT had only a 3.0% (95% CI, 2.1%-3.9%) higher probability of comprehensive CVRF assessment, 2.6% (95% CI, 1.6%-3.5%) higher risk of uncontrolled CVRFs, and 5.4% (95% CI, 4.2%-6.6%) lower risk of untreated CVRFs. CONCLUSIONS AND RELEVANCE: These findings suggest that veterans with prostate cancer had a high rate of underassessed and undertreated CVRFs, and ADT initiation was not associated with substantial improvements in CVRF assessment or management. These findings highlight gaps in care and the need for interventions to improve CVRF mitigation in this population.