Food Additives and Hyperactive Children (Conners, 1980) is the first book-length attempt to evaluate Feingold's additive and salicylate-free Kaiser-Permenente diet for the treatment of hyperactive children, and as such it requires critical scrutiny. The studies reported in the book appear to be open to criticism from a number of points of view. It is argued that the studies as reported do not constitute a methodologically adequate test of Feingold's hypothesis that many hyperactive children are hypersensitive to artificial colours and flavours and other chemical additives and naturally occurring substances in foods and that it is thus premature to reject the hypothesis on the grounds presented here. It is argued, further, that Feingold's approach to the environmental aetiology of childhood hyperactivity is too limited and may for this reason lead to a failure to discover and eliminate other possible environmental causes of this increasingly prevalent condition.