Hollow chitosan (CS) microspheres were obtained using an inverse-emulsion crosslinking method. The temperature and viscosity of the CS emulsion affected the characteristics of the derived microspheres. The microspheres were characterized by differential scanning calorimetry, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy, optical microscopy, scanning electron microscopy (SEM), and laser particle size analysis. FT-IR indicated the sequence of transformations taking place before, during, and after the crosslinking of CS. Optical microscopy and SEM confirmed the spherical morphology of the gel. The formation of hollow microspheres with a single cavity was identified by SEM. The CS microspheres exhibited a narrow particle size distribution. Furthermore, particle size could be controlled by changing the stirring speed. (C) 2009 Wiley Periodicals, Inc. Adv Polym Techn 28: 40-47, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20145