PURPOSEWe determined trends in life expectancy and cause-specific late mortality after autologous blood or marrow transplantation (BMT) performed over a 30-year period, using the BMT Survivor Study.METHODSWe constructed a cohort of 4,702 individuals with hematologic neoplasms who lived ≥ 2 years after autologous BMT performed between 1981 and 2014 at three transplant centers. The end of follow-up was April 19, 2021. The primary exposure variable was autologous BMT performed in four eras: 1981-1999; 2000-2005; 2006-2010; and 2011-2014. Vital status and cause of death were obtained from National Death Index Plus program and Accurinct databases.RESULTSThe median age at BMT was 53 years (range, 0-78 years), 58.7% were male, 67.8% were non-Hispanic White, and 28.3% had undergone transplantation between 2011 and 2014. Autologous BMT recipients experienced a 7-year reduction in life expectancy. The adjusted hazard of 5-year all-cause mortality declined over the four eras (reference: 1981-1999; hazard ratio [HR]2000-2005 = 0.77; 95% CI, 0.62 to 0.94; HR2006-2010 = 0.64; 95% CI, 0.51 to 0.79; HR2011-2014 = 0.56; 95% CI, 0.45 to 0.71; Ptrend <.001), as did years of life lost (5.0 years to 1.6 years). The reduction in all-cause mortality was most pronounced among those transplanted for Hodgkin lymphoma or plasma cell dyscrasias, but was not observed among those transplanted for non-Hodgkin lymphoma or those conditioned with total-body irradiation. We also observed a decline in late deaths because of infection (Ptrend <.0001; primarily for BMTs before 2006) and subsequent neoplasms (Ptrend =.03; confined to decline in therapy-related myeloid neoplasm-related mortality) but not because of cardiovascular or renal disease.CONCLUSIONLate mortality among autologous BMT recipients has declined over a 30-year period. However, ongoing efforts are needed to mitigate development of infections, subsequent neoplasms, and cardiovascular and renal disease to further reduce late mortality.