Abstract: Treatment of Parkinson's disease, parkinsonian syndromes, extrapyramidal syndromes, obsessive-compulsive disorder and syndromes, and frontal and subcortical dementias, with imidazo?1,2-a!pyridine-3-acetamide derivatives of the formula (I) ##STR1## wherein Y represents a hydrogen or halogen atom or a C.sub.1-4 alkyl group, A represents naphthyl or C.sub.6 H.sub.3 X.sub.1 X.sub.2, wherein each of X.sub.1 and X.sub.2 independently of one another is a hydrogen or halogen atom, a C.sub.1-4 alkoxy group, a C.sub.1-6 alkyl group or CF.sub.3, CH.sub.3 S-- , CH.sub.3 SO.sub.2 -- or --NO.sub.2, and each of R.sub.1 and R.sub.2 independently of one another represents either a hydrogen atom, or a straight or branched C.sub.1-5 alkyl group which is unsubstituted or substituted by one or more halogen atoms, hydroxyl, --N(C.sub.1-4 alkyl).sub.2, carbamoyl or C.sub.1-4 alkoxy groups, or an allyl group, or a propargyl group, or a C.sub.3-6 cycloalkyl group, or a benzyl group, or a phenyl group, not both R.sub.1 and R.sub.