Diaper dermatitis is one of the most common skin problems in infants and children, affecting between 7% and 35% of infants. This randomized clinical trial compared the efficacy of hydrocortisone 1% ointment with that of human breast milk in treating acute diaper dermatitis in infants ages 0 to 24 months. Infants with diaper rash were treated with either hydrocortisone 1% ointment (n = 70) or human breast milk (n = 71) for 7 days. Improvement in the rash from baseline was seen in both treatment groups on days 3 and 7; there was no significant difference in total rash scores on days 3 and 7. Treatment with human breast milk was as effective as hydrocortisone 1% ointment alone. Human breast milk is an effective and safe treatment for diaper dermatitis in infants.