Scouts may be taken on trips to sexual health clinics after new guidance was issued to help young people Be Prepared.
The visits are suggested for explorer scouts aged 14 to 18 in the advice issued today by The Scouting Association.
Chief Scout Peter Duncan said: "We must be realistic and accept that around a third of young people are sexually active before 16 and many more start relationships at 16 and 17.
"Scouting touches members of every community, religious and social group in the country so adults in Scouting have a duty to promote safe and responsible relationships and, as an organisation, we have the responsibility to provide sound advice about how to do that."
The new guidance says scout leaders can even give out condoms but "only if they believe the young person is very likely to begin or continue having intercourse with or without contraception".
Contraception can only be offered if without it "their physical or mental health are likely to suffer".
The guidance says leaders should "encourage young people to resist pressure to have early sex" and to talk to their parents or carers but "should be prepared to offer appropriate information" if it is needed.
A visit to, or by, a sexual health clinic may help to "break illusions of what these services are and improve the uptake of advice".
The Scouting Association said young people may feel more comfortable discussing sexual issues in the informal setting of a Scouts group.
Mr Duncan said: "I firmly believe that the confidence, skills and self esteem young people gain through the incredible range of activities Scouting offers is the best way to equip them not to feel pressured into a sexual relationship before they are ready."
Other suggested activities for explorer scouts include discussions about how different religions view sex and roleplays on learning to say no.
The new guidance includes advice for leaders of scouts of all ages.
Leaders of scouts aged 10 to 14 are told youngsters may seek advice and should be given information and suitable local contacts.
Activities may be planned to ensure youngsters are able to make "safe and informed decisions".
Leaders of beavers and cubs - ages six to 10 - are told it is unlikely they will need to take "positive action".
Dr Karla Blee, 25, is a trustee on the Avon County Scouts Executive who helped to draft the guidance.
"At a time when 10 per cent of sexually active teenagers are estimated to have a sexually transmitted infection and 50% of teenagers say they do not use contraception, it is absolutely right that The Scout Association gives its young people the information they need to stay safe while ensuring they develop the confidence and self esteem to resist the pressures to become sexually active too early," she said.
Minister for young people Beverley Hughes welcomed the new guidance.
"While our teenage pregnancy rates are coming down and are at the lowest rate for over 20 years, there is much more to do to ensure young people have the knowledge they need to prevent early pregnancy and look after their sexual health.
"This guidance underlines the consensus among young people, parents and professionals on the importance of providing accurate information and advice on sex and relationships.
"It will also make a really valuable contribution to the work of local teenage pregnancy strategies in reaching out to all young people in their communities."
Explorer scout Amy Brunsdon, 17, said: "Many young people are already sexually active, and it is great news The Scout Association is providing this new advice.
"We do get some information at college, but too often it focuses on the biology, not issues like emotional pressure.
"It is so much more meaningful to discuss these issues with people of our own age and in a context we know we can trust."