The aim was to describe aspects of students’ knowledge of sexuality and contraception and their sexual behaviour in schools in Ségou, Mali. </span><b><span style="font-family:Verdana;">Materials and Methods:</span></b><span style="font-family:Verdana;"> This was a one-pass cross-sectional survey with reasoned choice at the first level and random choice at the second level over a 3-month period from January 2013 to March 2013. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> The majority of the students involved in our study reside in the commune of Ségou, 90.4%. The average age of our students was 18. The female sex was the most represented in our study with 59.7%. The majority of students had casual sex at 60.3% and 70.9% irregularly. The change of sexual partner affected 47.9% of schoolchildren. Of our sexually active students, 72.6% had sexual partners and 37.4% had more than 2 partners. The main sources of information are respectively the media with 72.1% followed by teachers with 12.9% and friends with 09.7%. Among the most well-known contraceptive methods, condoms rank first with 72.6%, followed by injectable with 72.0%. 70.6% of the population had not yet used a contraceptive method at first sexual intercourse and in 72.9% of cases was condoms. The most cited source of contraceptive supply is pharmacy with 49.5% followed by family planning centres and maternity wards at 16.2% and shops at 16.2%. </span><b><span style="font-family:Verdana;">Conclusion</span></b><span style="font-family:Verdana;">: The referral of young people to approved health facilities for contraception could prevent them from risky sexual behaviours.