OBJECTIVES: Cancer patients are substantially more likely to file for bankruptcy than persons without cancer, but little is known about the determinants of bankruptcy among the general population of cancer survivors. METHODS: In order to better understand whether disparities in risk for bankruptcy exist among patients with cancer, we conducted a population-based cohort study of adults diagnosed with a first-primary invasive cancer in the Western Washington Surveillance Epidemiology and End Results (SEER) region between 1995 and 2009 and linked their cancer registry data to records of the US Bankruptcy Court. Using multivariable adjusted competing risk regression models, we estimated the hazard ratio (HR) and 95% confidence interval (CI) for the association between various sociodemographic and tumor characteristics and bankruptcy. RESULTS: Of 231,673 persons diagnosed with cancer, a total of 4,728 (2.0%) filed for bankruptcy. Compared to non-Hispanic White patients, African Americans (HR 1.88, 95% CI 1.64-2.16), Hispanics (HR 1.82, 95% CI 1.49-2.22), and American Indian/Alaska Native (HR 1.63, 95% CI 1.28-2.07) patients were all at substantially higher risk of bankruptcy. In addition, individuals living in higher income areas, males, and married cancer patients were at reduced risk of filing for bankruptcy, compared to females and unmarried patients respectively. CONCLUSIONS: The financial burden of cancer may disproportionately result in bankruptcy filings for minorities and cancer patients of lower socioeconomic position. These results highlight the need for policy changes protecting the financial health of cancer survivors.