The teenage fertility rate fell precipitately in Sweden after 1966 and is now one of the lowest in Europe. This decline can be seen in the context of major reforms enacted in 1975 whereby the school sex-education curriculum was revised, contraceptive services were improved, and abortion was provided free and on demand. By means of microsimulation, the possible roles of contraception and induced abortion in causing teenage fertility to fall are examined. Before 1975, the decline appears to have been caused primarily by an increase in the number of induced abortions. After that date, however, an increase in the use of highly efficient methods of contraception led to a decline in the pregnancy rate in such a way that, even though the proportion of teenagers who sought abortion increased, the abortion rate declined. Parallels are drawn with the experience of other European countries, and contrasts with that of the United States, where no such developments have occurred, are noted.