A study was conducted to see if children in a 6-week Head Start program in Canton, Ohio would make greater cognitive gains in an academically structured curriculum than in a less structured one. With the exception of the educational program, all other aspects of the traditional Head Start program remained the same for all children. Inservice training programs for teachers and aides were conducted and parent-teacher meetings were encouraged. Fifteen children in each of eight Bereiter-Engelmann program centers and 15 in each of eight control centers were pretested and posttested on the Caldwell Preschool Inventory and the Engelmann Concept Inventory. Results of statistical analysis of the data by matched pairs showed that, over a short term, children in the structured curriculum made greater gains than those in the unstructured program. A followup study was not attempted so that it was not learned whether gains would be sustained after a year or more in school. Other study findings suggest that elementary school teachers, rather than those trained for kindergarten, most easily adapt to structured preschool programs and that neighborhood women may profitably be recruited and trained to be teacher aides. Further investigation into the nature of the optimal type of Head Start curriculum is urged. (MS)