Block copolymers containing polyamide-3 as one constituent have been synthesized by anionic polymerization. The reaction conditions for the two blocks have to be quite different. Chemical heterogeneity of the products has been studied using thin-layer chromatography. The cyclohexane-insoluble parts of poly(styrene-b-acrylamide) and poly(alpha-methylstyrene-b-acrylamide) with high incorporation rate of polyamide as well as the acetonitrile-insoluble part of poly(methyl methacrylate-b-acrylamide) are mainly block copolymers. Infra-red measurements confirm these results.