For each of 4 years varying numbers (from 45 to 750) of 3- to 5-year-old children, mostly Mexican-American, Spanish speaking, participated in a program aimed at language development. Classes met 3 hours daily, five times a week, in small discussion-and-activity groups that included five children and one adult. The Peabody Picture Vocabulary Test was used as a pretest and posttest measure. On the pilot project nearly every child raised his IQ by 10 to 20 points. For the second year, there were negligible gains, possibly due to the brevity of the program (2 to 5 months) and the teachers' lack of nursery experience. The third year's test results, which were divided into three ethnic groups (Caucasian, Negro, and Mexican-American), were compared. The groups differed significantly on the pretest but not on the posttest. All groups gained significantly. The same procedure was followed the fourth year, and all groups gained significantly. (JS)