Although the term "challenge course" has been used for a wide array of programs used with diverse clientele, they all have in common the use of experiential education in an outdoor setting aimed primarily at increasing subjects' self-esteem, trust in others, and the diminishment of risk- taking behaviors. The origin of contemporary challenge programs can be traced to the so-called wilderness therapy, Outward Bound. Program activities typically consist of individual and group exercises that challenge individuals to perform physical and mental tasks they may never before have undertaken. Individual exercises may include walking along cables strung 20-30 feet above the ground or jumping or falling from a similar height. Group exercises typically focus on the sharing of responsibility and the solving of problems as a team. Most evaluations of challenge programs have targeted wilderness programs similar to Outward Bound. Evaluations are usually favorable. The effectiveness of such programs may be due to the fact that activities combine the use of physical, affective, and cognitive domains. The article concludes with a brief discussion of the implementation of challenge programs. 22 references