New palladium-polypyrrole (Pd/PPy) nanocomposites have been studied in cyanation of aryl halides with K4Fe(CN)(6) and showed high catalytic efficiency. Aryl iodides, bromides, and chlorides are active. The reaction can be performed both in organic solvents and in water; in the latter case, the catalyst was immobilized on graphite support. The cyanation of inactivated aryl chlorides is of special importance as only a few publications dealing with efficient cyanation of aryl chlorides are available, in which expensive and poisonous phosphine ligands and non-aqueous solvents are used. The influence of the morphology of the catalyst on its efficiency in cyanation was investigated, and it was revealed that PPy spheres of about 30 nm in diameter with palladium nanoparticles of 1.2 nm in size are more efficient than bigger polymer ones (about 60 nm in diameter). Palladium content in polypyrrole spheres does not influence the yield of nitriles. (C) 2013 Elsevier Ltd. All rights reserved.