Addition of parathyroid hormone (PTH) to bone organ cultures markedly increased the incorporation of 3H-glucosamine into nondialyzable polysaccharides. DEAE-cellulose chromatography resolved the labeled material into four peaks. A 4-fold increase in radioactivity was demonstrated in one of these peaks. The material in this peak was tentatively identified as hyaluronic acid. The other peaks contained glycoproteins and sulfated acid mucopolysaccharides, in addition to other yet unidentified materials. Collagen synthesis as measured by 14C-proline incorporation into 14Chydroxyproline was markedly decreased with PTH treatment.