Model programs and standards for substance abuse prevention have been identified by a number of federal agencies. The study reported here assessed two methods of delivery of one such program, Life Skills Training (LST), implemented in nine rural disadvantaged school districts. The results indicate that neither standard LST nor an infused LST delivery method was found effective for the entire sample, although some encouraging results were found for the females in the study. This study, conducted by researchers independent of the LST program, is useful for school decision makers in determining what programs are most effective with which groups. It included all students with parental permission, controlling for prior use levels, unlike some previous LST studies. The results of the program, as implemented by regular classroom teachers, reflect many issues relevant to recruitment, training, implementation, adaptation, and institutionalization of prevention programming. (Contains 2 tables.)