Diaper dermatitis, also know as nappy rash, is an inflammation of the skin covered by nappy. It probably results due to an interaction of multiple factors like increased wetness, elevated pH due to urine, fecal enzymes and microorganisms under the nappy. It manifests as an erythematous rash occurring on the convex surfaces of skin under the nappy. Rashes resembling nappy dermatitis can also be caused by some diseases which may have serious systemic manifestations. Therefore it is essential to differentiate and treat them. The principle of treatment of diaper dermatitis is to keep the skin in the nappy area as dry as possible with frequent nappy change. The superabsorbent disposable diapers are known to reduce the incidence of diaper dermatitis. Barrier creams to protect the infant's skin and mild topical corticosteroids to reduce the inflammation are mainstays of therapy. The incidence and severity can be reduced by keeping the skin dry under the nappy and protected from irritants and infections.