The current study characterizes cognitive and psychiatric status in hematopoietic stem cell transplantation (HSCT) patients shortly before and after transplant. Thirty adult patients were assessed prospectively 1-2 weeks before transplantation and 100 days posttransplantation on neuropsychological and psychiatric measures. Before transplant, participants showed mild impairments on several neuropsychological measures, with the poorest performances occurring on learning and attention. Psychiatric functioning was significantly elevated compared with normative data. Significant improvements, however, were observed on neuropsychological measures by 100 days after transplant. Depression and anxiety scores also improved. Candidates for HSCT experienced mild diffuse cognitive dysfunction and psychiatric morbidity before the procedure, but these symptoms significantly improved by 3 months following their transplant in this small sample. Education about these possible pretransplant sequelae and the potential for rebound may be helpful to patients and families as they prepare for this treatment and the recovery period.