The effectiveness of a token economy system in producing improvement in the academic performance of children with Down's syndrome was tested. One group of seven children received token reinforcement for correct responses and showed significant improvement both in arithmetic and language. A second matched group of six children received only verbal praise for correct responses to the same instructional materials and failed to improve in arithmetic but showed significant gains in language. Re-test scores one year later revealed that the Token Group maintained its gains in both subjects whereas the language performance of the No-Token Group showed a significant decline.Behavior modification research with children of normal intelligence (e.g., Haring, Hayden, and Nolen, 1969;Miller and Schneider, 1970;Chadwick and Day, 1971) has amply demonstrated the effectiveness of token economy systems in producing improvement when successful performance on academic subjects is selected as the "target behavior" for modification. There are few comparable studies with retarded children (e.g., Birnbrauer, Wolf, Kidder, and Tague, 1965). The purpose of the present study was to provide additional empirical data bearing on this problem.Specifically, an attempt was made to test whether a group of children with Down's syndrome would make significantly greater gains in certain school subjects when such learning was supported by a token economy system than when the same material was taught to a second group of comparable children without the support of a 1The authors are indebted to the following for their indispensible assistance in the collection and analysis of the data presented in this report: