To compare alcohol cleaning and natural drying of newborn umbilical cords. Prospective, randomized controlled trial. Tertiary-level university teaching hospital and level II community hospital. Of 1,876 singleton full-term newborns enrolled, 1,811 completed the study. Newborns, from birth until separation of the cord, were randomized to either (a) umbilical cleansing with 70% isopropyl alcohol at each diaper change or (b) natural drying of the umbilical site without special treatment. Umbilical infection, cord separation time, maternal comfort, and cost. No newborn in either group developed a cord infection. Primary care providers obtained cultures for cord concerns in 32 newborns (1.8%), with colonization for normal flora, Staphylococcus aureus, and Group B streptococcus proportionately equal in alcohol and air dry groups. Cord separation time was statistically significantly different (alcohol group, 9.8 days; natural drying group, 8.16 days; t = 8.9, p = < .001). Mothers described similar comfort with cord care and relief with cord separation. Costs of alcohol drying while in the hospital were greater than those of natural drying. (a) Evidence does not support continued use of alcohol for newborn cord care; (b) health care providers should explain the normal process of cord separation, including appearance and possible odor; and (c) health care providers should continue to develop evidence to support or eliminate historic practices.