['Some patients needing a kidney transplant have used cyclophosphamide before the transplant. Long-term bone marrow damage associated with cyclophosphamide could manifest with myelotoxic complications after transplant in the context of the immunosuppressant, but evidence for this has not been published.', 'We performed a retrospective, single-center analysis of renal transplant recipients with prior cyclophosphamide exposure and compared posttransplant short-term outcomes to a random control group (clinical outcomes identified by searching automated electronic databases).', 'Sixteen recipients had taken cyclophosphamide before the transplant and were compared with a control group of 32 patients. Hospitalization rates were equal, and although there were 3 times more hospitalizations secondary to an infective course in the cyclophosphamide group, this did not achieve significance (0.63 vs 0.22; P = .147). There was no difference in rates of bacteriuria, cytomegalovirus, or Polyomavirus. The cyclophosphamide group was at significantly greater risk of needing a blood transfusion immediately after the transplant (average number of units of blood per patient, 0.44 vs 0.19; P = .038). Also, they were 3 times more likely to require anemia treatments 1 year after the transplant (average number of anemia treatment medications, 0.75 vs 0.25; P = .014). Full blood count parameters, graft function, and graft and patient survival at 1 year posttransplant were equal.'] Is cyclophosphamide exposure pretransplant associated with complications in the first year after kidney transplant?