Diaper rash commonly affects infants. The largest reported group survey of diaper rash incidence recently took place in Great Britain.30 Twelve thousand parents of newborns were queried for a period of 4 weeks after their child's birth. In this survey, 25% of parents noted diaper (nappy) rash at this early age, in contrast to previous studies describing diaper rash incidence at its peak in the range of ages 8 to 12 months.13, 23 Although many cases of diaper rash are transient, last 1 day, and resolve without treatment,13 caregiver concern about diaper rash is reflected by (1) the ever-increasing array of over-the-counter products promising rapid diaper rash relief, (2) a burgeoning of internet sites devoted to diaper rash, and (3) a multitude of visits to nurse practitioners, family practitioners, pediatricians, and dermatologists for diagnosis and treatment of diaper rash. This article discusses common and rare causes of diaper rash, suggests an approach to the infant or toddler with diaper rash, describes helpful treatments for diaper rash, and reviews hazardous or questionable treatments and practices. Several sources for reputable medical information are provided.