Scout Association figures released today show there are now 457,000 young people involved with Scout movements across the UK but its waiting list now stands at 51,000, the highest level in the organisation's 110-year history.
The youth organisation has called for more volunteers to come forward to cope with demand.
Tim Kidd, the Scout Association's chief commissioner, said that although it currently has 154,000 volunteers, another record high, many can only offer limited time.
"Our adult volunteers today seek much more flexible volunteering arrangements than in the past, so that they can fit it around their busy lives," he said.
"Many adults who are signing up with the Scouts have a limited amount of time to donate to us, and so we need more volunteers as a whole in order to accommodate the continued demand for Scouting among young people."
An estimated 17,000 volunteers are needed to meet demand, with waiting lists highest in Surrey, Hertfordshire and Hampshire.
Kidd said that as well as Scout group leaders, the organisation is also looking for volunteers to take up administrative and trustee roles.
Chief Scout Bear Grylls added: "Our challenge is to keep recruiting even more adults as we've got 51,000 young people wanting to join and benefit from what Scouting offers. Volunteering changes us all for the better. Please join me."
The total Scouts membership, which includes trustees, volunteers and young people, is 618,000, up 7.8 per cent in the 12 months to the end of January 2017.
Over this period 7,000 young people joined, 2,000 of which signed up to join the Cub Scouts, which is for eight- to 10-year-olds and has a total of 158,000 members. Girls and woman now make up 27 per cent of the organisation.