Chitosan microspheres of nifedipine and nifedipine cyclodextrin complexes were prepared by the glutaraldehyde cross-linking of chitosan. Microspheres having different degrees of swelling were made by varying the cross-linking density. Drug incorporation efficiencies exceeding 70 % could be achieved for this drug. In vitro release rates were influenced by the cross linking density, particle size and initial drug loading in the microspheres. While the solubility of nifedipine was enhanced by inclusion int a cyclodextrin complex, the drug release from the complex was significantly reduced. In addition the drug release mechanisms were discussed.