Chitosan/apatite composites are attracting great attention as biomaterials for bone repair and regeneration procedures. The reason is their unique set of properties: bioactivity and osteoconductivity provided by apatite and resorbability supplied by chitosan among others. Thus, in this work chitosan/apatite and chitosan/Si-doped apatite composites were prepared and characterized. Particle size, surface area, in vitro physiological stability, enzymatic biodegradation and bioactivity were evaluated. Unimodal particle size distribution was obtained for composites with high chitosan/apatite ratios while bimodal distribution was present in composites with low chitosan/apatite ratio. Physiological stability decreased with Si-doping and with the chitosan content. Acetylation degree and molecular weight of chitosan did not affect in vitro stability. Rate of enzymatic degradation increased with the chitosan content in composites. Si-doped apatite composites also showed increased degradation with respect to non-doped ones. The bioactivity of the composites was evidenced by the deposition on their surface of a calcium phosphate layer with apatite morphology after immersion in simulated body fluid. Both, biodegradation and bioactivity were dependent on the molecular weight of the polymeric chitosan matrix. These results suggest that the chitosan/apatite composites obtained are promising materials for bone regeneration applications