Teenage pregnancy has become a major public health problem in the United States. A study was conducted to assess an intervention based upon computer-assisted instruction (CAI) to avert teenage pregnancy. Social learning and decision theory were applied to mediate the adolescent environment through CAI so that adolescent development would be enhanced, fostering mature decision making. A non-random comparative design was implemented in five high schools on the island of Oahu. High school students (N=718) served as either control subjects or as experimental subjects who played one of two computer games, either Baby Game or Romance. Experimental subjects rated the games favorably. Compared to controls, significantly more of the Baby Game players could identify the time required for child care, and the costs for childbirth, care for the first year of life, and raising a child to age 18. Compared to controls, significantly more of the Romance players reported they would ask a health professional for birth control advice, find it easy to get and use birth control, and identify effective and noneffective methods of birth control. Informal follow-up interviews revealed that pregnancy rates were lower in two settings where the games had been implemented for over one year. These preliminary findings suggest that CAI may be a viable intervention to avert teenage pregnancy. Further research is being planned. (NB)