A programed course in general histology was completely developed by dental schools in the United States and Brazil. A group of international experts specified the course objectives, wrote and taped scripts for a series of 28 lectures of 50 minutes each, developed slides to accompany the lectures, prepared microphotographs and scripts to explain and illustrate laboratory microscope exercises, and devised daily quizzes. Evaluation of the program after its use showed that successful scripts could be cooperatively developed and easily translated to other languages and that the preparation cost was minimal. Daily quizzes contributed to increased achievement, and quiz scores correlated positively with final exam performances; quiz results also helped to identify weak students early in the term and to highlight areas where remedial attention was needed. Students in general performed well; the lower ability students achieved more than they had in conventional instructional programs. Thus it appears that programed instruction can improve educational efficiency by providing better instruction to more students at lower costs and in less time, and it is recommended that hemispheric cooperation be developed for the production of additional programed instruction and long-range communications. (LB)