Our objective was to characterize the risks of maternal deaths in cancer patients compared to the general population using a large population-based cohort.Female patients with a cancer first diagnosed at ages 15 to 39 years between 2000 and 2016 (N = 240,561) from the surveillance, epidemiology, and end results database were extracted, among which 165 maternal deaths were observed.We found Hispanic ethnic groups, advanced cancer stage, receiving chemotherapy were associated with a higher risk of maternal deaths compared to the general the United States population. Patients with cancers of the respiratory system were at the highest risk of maternal deaths, followed by cancers of the digestive system, and hematological malignancies.Abbreviations: CI = confidence interval, HR = hazard ratio, SEER = surveillance, epidemiology, and end results, SMR = standardized mortality ratio, US = the United States.