The North Karelia Youth Project was a 2-year intervention study aimed at preventing cardiovascular diseases risk factors among 13-year-old adolescents at the project's start. It was carried out during the years 1978 to 1980 in the county of North Karelia, Finland. The smoking prevention portion of the program was aimed at teaching children skills necessary to handle the social and psychological pressures associated with starting to smoke. During the 2-year program, 10 sessions were carried out in two schools by the project team and by specially trained peer leaders. In about half of the remaining 22 schools in North Karelia, a five-session program was carried out voluntarily by the teachers. After the program, 20% of the children in the two schools where the direct intervention was carried out reported smoking at least once a month. The same rate also was observed in two matched schools representative of the rest of the schools in North Karelia. In two other matched control schools in another county, 30% of the pupils reported to be smokers by the same criteria. Two years after the program (4 years after the beginning of the program), the reported smoking rates in the different school groups were 27, 26, and 37%, respectively. The results of this pilot study indicate that it is possible to reduce smoking onset by this kind of innovative program and that the beneficial effect can last several years.