Cross-sectional survey using a self-administered anonymous questionnaire was conducted to assess knowledge, attitude and practice of contraception and sexuality. The questionnaire was filled out in April 2000 by 752 high school students in Butajira, Ethiopia. The mean age of the subjects was 17.1 years. One hundred thirteen never married students (17.5%) claimed to have experienced intercourse; 22.0% of boys and 8.8% of girls. Sexual abstinence was not dictated by perception of risk. About 78% of boys and 91% of the females did not use modern contraceptives at their last sexual intercourse. Nine female students claimed to have been pregnant: two had delivered and seven had induced abortion. The most important reasons for non-use of contraception were lack of adequate knowledge, partner refusal, perception of diminished pleasure and embarrassment to buy. Seventy-one percent of the respondents knew at least one contraceptive method. Over half of the students had no source of information on sexuality and for 25.9% school was the main source of information. The attitude to sexuality was conservative, but liberal to introduction of sex-education at secondary schools. Higher percentage of boys admitted that they had exaggerated their response on sexual matters; girls admitted under-reporting. It is recommended that sex and family life education be discussed openly in schools and included in curricula.