CaSiO3/apatite composites prepared by a biomimetic method were used to fabricate Poly-l-lactic acid (PLLA)/CaSiO3/apatite composite films via a solvent evaporation technique. The in vitro bioactivity and mechanical properties of the films were investigated. The results suggested that the composition and particle size of the CaSiO3/apatite composites were dominated by the powder/solution ratio used during the immersion. The ability of the films to form apatite in vitro was dependent on the β-CaSiO3 content. The introduction of inorganic components into the PLLA matrix resulted in a significant drop in tensile strength, while better dispersion and more apatite content enhanced the tensile strength.