Few studies have compared the effectiveness of washing with either soap and water or disposable wet wipes. The objective of this study was to compare the effectiveness of washing with either soap and water or disposable wet wipes in reducing microorganisms in the groin and perineum of hospitalized patients, which could potentially reduce the risk of hospital-acquired urinary tract infections. In this crossover, block-randomized trial, skin swabs from the groin and perineum areas of patients were obtained before and after these areas were washed with either soap and water or disposable wet wipes. Columbia agar plates and CHROMagar Orientation Medium (Becton Dickinson; Franklin Lakes, NJ) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry procedures were used to identify species of microorganisms. Fifty-eight paired skin swabs were obtained. Both washing methods resulted in a statistically significant reduction in the amount of all microorganisms, including microorganisms with the potential to cause urinary tract infections. New species were observed after using both washing methods. No statistically significant difference in the removal of microorganisms was observed between the two washing methods. The two washing methods appear to be equally efficient in removal of microorganisms in the groin and perineum areas, including microorganisms that potentially could cause hospital-acquired urinary tract infections.