Polymer-supported oxidic osmium catalysts based on cross-linked poly(4-vinyl pyridine) were synthesized by various routes and characterized by a number of physical techniques (Raman, IR, XPS, 1 3 C and 1 5 N solid-state NMR spectroscopy). Model compounds of type Os 2 O 6 L 4 (L = pyridine, 4-iso-propyl pyridine, and 4-tert-butyl pyridine) were obtained under the conditions of the catalyst synthesis. The catalytic systems were successful in the dihydroxylation of alkenes.