In Latin America only some educational programs, based on systematic r
esearch on the needs of adolescents, have been developed and even fewe
r have been adequately evaluated. Most of the evaluations present seri
ous methodological defficiencies and refer mainly to sexual and contra
ceptive knowledge, and in less degree, to behaviors related to initiat
ing sexual activities and contraceptive use. ''Planeando tu Vida'' is
a sex educational program developed on the bases of exploration resear
ch carried out in Mexico. It was evaluated in 1632 students of public
high schools. Subjects were asigned at random to the control and exper
imental groups. A baseline, an evaluation immediately after finishing
the course and a six months follow-up were carried out. The results sh
ow that: The courses had no effect on the sexual activity of the adole
scents. When they attend the course before having their sexual debut,
the possibility of using contraceptives is significantly increased. He
adolescents who participated in the course had a higher degree of kno
wledge about sexuality and contraception and a higher level of percept
ion of access to contraception and of contraceptive use in the follow-
up. The results obtained in this study bear special relevance in Latin
american countries in which sex education is not integrated to most sc
hool programs. Based on the results of this study, the Instituto Mexic
ano de Investigacion de Familia y Poblacion (IMIFAP) is developing pro
grams and matherials for children from preschool through high school i
ncluding teachers and parents.