Mazindol is an example of a nonphenylethylamine compound which nevertheless exhibits a biochemical and behavioural profile similar to that of damphetamine. Pharmacological analysis has implicated a possible role for dopaminergic mediation in the reduction of food-intake produced by mazindol. However, side-effects, including changes in general locomotor activity, are important factors to consider in relation to the anorectic activity of pharmacological agents. Mazindol reduces food-intake and this effect is antagonized by spiroperidol, a dopamine receptor blocker, even when both agonist and antagonist are given at doses which do not alter locomotor activity. Monitoring the anorectic action of drugs in a free-feeding situation, in relation to the distribution of eating and non-eating episodes, is suggested as a valuable method for understanding the basis of anorexigenesis. Furthermore, concurrent monitoring of additional behavioural responses, including drinking behaviour and locomotor activity, should add considerably to a full account of the mechanisms of action by which drugs reduce food intake.