Exogenous and endogenous factors have been implicated in allergic contact dermatitis (ACD); this review explores the sex of the individual as a possible endogenous factor. While there is a clinical impression that women are more skin-reactive than men, upon review this hypothesis appears oversimplified. This review explores sex differences in controlled testing of adult ACD, occupational ACD and juvenile ACD. Further, geographical location and socioeconomic and cultural factors in relation to sex differences in allergic contact dermatitis are discussed. We conclude that female sex could be a factor predisposing to allergic contact dermatitis not so much because of possible differences in intrinsic skin characteristics between the sexes, but more because of different exposure patterns. This conclusion has practical consequences regarding product labelling requirements, occupational risk assessment and legislation.