Investigated were the feasibility and effectiveness of using programed materials with concomitant laboratory exercises in teaching genetics on the secondary level. Students from two white and two Negro high schools in the Atlantic Public School System participated, with one control and one experimental biology class in each school taught by the same teacher. In the experimental group (N=77) the programed material developed by the author was the sole instructional device, while the control group (N=89) was taught comparable materials by conventional methods. The results indicated that (1) there was no significant difference in achievement, but the experimental group attained this level in one-half the time, (2) there was no relationship between sex and final achievement, (3) academic average was a successful predictor of success in the program, (4) there was a positive relationship between reading score and achievement using the programed materials, (5) there was a negative correlation between time in the instructional program and achievement for the total group, and (6) there were no unusual administrative problems in presenting basic genetic subject matter with integral laboratory exercises in programed form. (DS)