Background: Racial and ethnic disparities in survival after first primary cancer diagnoses have been well documented. Yet comprehensive data for disparities after subsequent primary cancer (SPC) are lacking despite the growing burden of SPCs. Methods: This study included 230,370 persons diagnosed with one of the 13 common SPCs at ages≥20 years during 2000-2013 in 18 Surveillance, Epidemiology, and End Results registries. Cause-specific proportional hazards models were used to estimate HR (hazard ratio), overall and stratified by SPC types, comparing the risk of cancer or cardiovascular death in Hispanic, non-Hispanic Asian or Pacific Islander (API), or non-Hispanic Black (Black) persons to that in non-Hispanic White (White) persons. HRs were adjusted for sex, first primary cancer type and stage, age and year of SPC diagnosis (base model); and additionally household income, urbanicity, SPC stage, subtype, and treatment receipt (surgery, radiotherapy, chemotherapy) (final model). Results: During 54 months of median follow-up, 109,757 cancer deaths and 18,283 cardiovascular deaths occurred among persons with SPCs. Overall, HRs for cancer death were higher among Black (HR = 1.21, 95% CI = 1.18-1.23) and Hispanic (HR = 1.10, 95% CI = 1.07-1.13) persons compared with White persons, but lower among API persons (HR = 0.93, 95% CI = 0.90-0.96) in the base model. When stratified by SPC types, the increased HRs were evident for 10 of 13 cancers among Black persons with the greatest HR among those with uterine corpus cancer (HR = 1.87, 95%CI = 1.63-2.15) and for 7 of 13 cancers among Hispanic persons with the highest HR among those with melanoma (HR = 1.46, 95%CI = 1.21-1.76). For cardiovascular death, compared with White persons, the overall HR was higher among Black (HR = 1.42, 95% CI = 1.35-1.49) persons but lower among API (HR = 0.75, 95%CI = 0.69-0.81) and Hispanic (HR = 0.90, 95% CI = 0.84-0.96) persons. The risk of cardiovascular death was higher for 11 of 13 cancers among Black persons with the greatest HR among those with pancreatic (HR = 1.80, 95%CI = 1.17-2.75), thyroid (HR = 1.70, 95%CI = 1.12-2.57), and kidney (HR = 1.63, 95%CI = 1.38-1.93) cancers. Additional adjustments in the final model reduced the elevated HRs substantially especially for cancer death among Black or Hispanic persons, although the associations remained statistically significant for most cancers. Conclusions: Among persons with SPCs, Black persons had a higher risk of death from both cancer and cardiovascular disease, whereas Hispanic persons had a higher risk of death from cancer. Adjusting for differences in potentially modifiable factors attenuated the associations substantially, highlighting opportunities for interventions toward health equities among cancer survivors.