Numerous clinical trials have demonstrated that immunomodulating diets (IMDs) reduce treatment complications such as the risk of acquired infections, length of hospital stay, and wound complications in patients receiving planned surgery. These complications are possibly exacerbated by malnutrition at the time of surgery, resulting in decreased cell-mediated and humoral immune responses, which can be improved with the utilization of IMDs both prior to and following surgery. Although numerous randomized studies have investigated IMDs in the surgical setting, IMDs have not been well studied to evaluate whether their use improves outcomes for other patient groups with high incidence of malnutrition and acquired infections. Patients receiving stem cell transplantation following preparative myeloablative chemotherapy for treatment of a hematologic malignancy would be a prime example of another patient group who would share these characteristics. Given the proposed mechanism of action by which IMDs have aided recovery after surgery, it is reasonable to expect that IMDs may aid recovery after stem cell transplantation, and current preclinical and clinical data support the need for further clinical studies.