Objective

To present the changes in the prevalence of knowledge, attitudes and practices in high school adolescents in sexuality after an intervention process.

Methodology

Observational descriptive study. It was administered a questionnaire to 319 adolescents, attending three public schools, for five consecutive years as they progressed in school years (seventh to eleventh). Health promotion workshops were held. Changes in the prevalence were measured (identification of the menstrual cycle, emergency contraception and, condom protection, as well as parents' acceptance of contraception methods, having sex, reasons for do it and, whether they used protection in the first and last relationship). The results were compared by gender.

Results

The identification of emergency contraception was increased from 52% in seventh to 70% in eleven; also, the certainty of the condom protection (from 45% to 62%, respectively). The average of the prevalence of sexual intercourse was 24%, protection in the first relationship 52% and, in the last one was 81%; no statistical differences of these variables were found when comparing them by gender. Parents' perception of acceptance of planning increased from 45% to 79%.

Conclusion

The program results highlighted the need to strengthen the educational processes.