PURPOSE/OBJECTIVES To determine the efficacy of cover gowns and shoe covers in the prevention of infection in patients undergoing autologous bone marrow transplantation (BMT). DESIGN Randomized two-group controlled clinical trial. SETTING Adult BMT unit of a university teaching hospital in the Southeastern United States. SAMPLE 40 women and men receiving an autologous BMT for hematologic and solid tumor malignancies. Patients were assigned randomly to control or experimental groups. Thirty-one patients completed the study. Inclusion criteria required that patients be at least 18 years of age and not have received a previous autologous BMT. METHODS Data were collected from the patients' medical records. Characteristics of the distributions for the main research variables were compared between the control group (caregivers who wore cover gowns and shoe covers) and experimental group (caregivers who wore no covers). MAIN RESEARCH VARIABLES Time to first antibiotic treatment and length of antibiotic therapy. FINDINGS Cover gowns and shoe covers worn by caregivers provided no benefit for this group of 31 patients. The differences in time to first antibiotic and length of antibiotic treatment were not statistically significant between the two groups. CONCLUSIONS The mean and median number of hours to first antibiotic treatment for adult autologous BMT recipients in the control group exceeded the corresponding time for those in the experimental group by only one hour and four hours, respectively. The potential benefits and risks of cover gown and shoe cover usage by caregivers of autologous BMT recipients should be reexamined in larger randomized trials. IMPLICATIONS FOR NURSING PRACTICE The elimination of cover gowns and shoe covers in caring for patients undergoing autologous BMT will save nursing time and hospital resources as well as eliminate one isolation barrier experienced by patients.