The Leadership Laboratory for Student Development program, its rationale, objectives, and evaluation findings are discussed. The Leadership Lab, created to prepare a student leader to interact with a variety of people found in the typical school setting, provides students with structured learning experiences that progress from basic communication and group interaction to flexible leadership skills. Evaluation of the program was carried out simultaneously with the training sessions. These sessions were conducted at five high schools, two groups of students in each school, with approximately 17 students in each group. To measure change in interpersonal skills and personality characteristics, pretests were administered at the beginning of the training sessions, and the same tests were again administered at the end of the sessions. The instruments used in testing were the California Psychological Inventory (CPI) and the Intellectual Achievement Responsibility (IAR). Other instruments used to collect information were Student Survey, Student Questionnaire, and Exercise 22-A from the training manual. As not all students returned the posttest and some did not use the same identifying number of the pretest on the posttest, the sample of CPI and the IAR were biased. Results of the evaluation, which are given in 29 tables, showed that personality characteristics and interpersonal skills measured by the CPI did not change over the period of the training sessions to a significant degree, whereas personality characteristics and interpersonal skills represented by the IAR showed significant change. Copies of the CPI, a page of the IAR, the Student Survey, and the Student Questionnaire are provided. (DB)