Background: Cognitive impairment in survivors of blood or bone marrow transplantation (BMT) is well documented. However, to the authors' knowledge, the clinical relevance of self-endorsed cognitive problems and their relation to objectively assessed cognitive impairment is not known. Methods: The authors assessed cognitive impairment in 378 BMT recipients (median age, 52.2 years, 40% of whom were female and 68% of whom were non-Hispanic white) and 98 healthy controls at 5 predetermined time points: at baseline (before BMT) and at 6 months, 1 year, 2 years, and 3 years after BMT. Self-endorsed cognitive problems were evaluated using the Neuropsychological Impairment Scale (NIS) and correlated with a standardized 2-hour battery of objective cognitive testing at each time point. The authors examined the magnitude of difference in self-endorsed cognitive problems between BMT recipients and healthy controls, and the rate of change in scores over time. Multivariable analyses were used to identify clinical and/or demographic variables associated with self-endorsed cognitive problems. The authors also examined the association between cognitive impairment and returning to work after BMT. Results: Compared with healthy controls, BMT recipients endorsed more cognitive problems (P '.001) at all time points, and the rate of change in NIS scores was found to be significantly greater in BMT recipients. Fatigue was associated with greater endorsement of cognitive problems at 1 year after BMT (odds ratio, 4.23; 95% CI, 2.1-8.3 [P '.001]). Overall, there was a statistically significant, modest correlation noted between self-endorsed cognitive problems and objective cognitive impairment (range, 0.401-0.445 [P ≤.01]). Higher self-endorsed cognitive problems were associated with a 3.7-fold (P =.02) higher odds of not returning to work at 3 years after BMT. Conclusions: The results of the current study demonstrated that self-endorsed cognitive problems can help to identify vulnerable patient subpopulations for detailed cognitive assessment and possible cognitive remediation.