The purpose of this multiple baseline study was to examine the effect of bilateral hand splints on the persistent stereotypic hand movements of three adolescent girls with Rett syndrome. Among the most characteristic features of Rett syndrome are stereotypic hand-writing and hand-biting behavior and loss of previously acquired functional hand skills. The hand splints used in this study consisted of cuffs encircling the palm that positioned the subjects' thumbs in abduction. Duration percentages of subjects' stereotypic hand behavior and functional hand use were calculated from five-minute videotaped segments recorded during a finger-feeding condition and a free-time condition. All three subjects demonstrated a decrease in the amount of time spent in stereotypic hand behavior after application of hand splints, and one subject showed an increase in finger-feeding skills while wearing hand splints. Limitations of the study are discussed, and suggestions for clinical application and future research are offered.