The All Day Kindergarten (ADK) Program of the Columbus (Ohio) Public Schools was established to provide a full day of instruction for underachieving kindergarten pupils. The program concentrated on preparing pupils for successful learning experiences in first grade by providing them with an extra half day of instruction. The program served 571 children, with 18 teachers providing daily instruction for two groups of students in 18 Chapter 1 eligible elementary schools. Groups were limited to 15 pupils, and instruction time was 13.3 hours weekly. The All Day Kindergarten Program functioned during the 1986-1987 school year for 130 hours of instruction, with emphasis on activities that would increase language and reading development and enhance those skills needed; for success in first grade. For program evaluation purposes, pretests and posttests were administered to 396 students (who met the 80% attendance requirement; 379 students were present for both tests. The Normal Curve Equivalent (NCE) gain for these students was 3.0 points for each month of treatment--greatly exceeding the criterion of 1.0 NCE point that was the original program goal. Results suggest the efficacy of the All Day Kindergarten Program. Based on the evaluation results, a continuation of the program was recommended for the following school year. (A teacher census form, an inservice evaluation form, and a Chapter 1 parent involvement survey form are appended.) (NKA)