Although many photographs of allergic contact dermatitis on the palms have been published (1), clinically proved cases are rare. It seemed of clinical and medicolegal importance to demonstrate that sensitization can occur to an allergen applied only to the palm, as well as to confirm experimentally the accepted fact that allergic contact dermatitis can be elicited on the palm of a sensitive subject. This study investigated allergic contact dermatitis on the palm by experimental sensitization with a simple chemical, 2,4-dinitrochlorobenzene.