Chitosan (CHI) has been complexed with polyacrylic acid (PAA) in the presence of hydroxyapatite (HAP) to prepare composites intended for bone substitute applications. Thermogravimetric analysis of the composite showed that the presence of HAP had little effect on the degradation profile of the polyelectrolyte complex (PEC), except for the onset of degradation. Optimum compressive strength was observed for 70-weight percentage HAP filled PEC. The morphological analysis revealed that the HAP particles were uniformly distributed in the PEC matrix. The results indicate that HAP filled PEC of CHI and PAA could be prepared following the proposed simple route. (C) 2003 Kluwer Academic Publishers.