Chief commissioner Wayne Bulpitt was speaking at the launch of a new initiative to open new UK Scout Groups in 200 areas around the country.
He's concerned parents in underprivileged areas are put off by 'myths' about the Scouts.
He said: "There is a danger that in some areas, Scouting will die out.
"Scouting is for boys and girls and is open to all.
"Some people think it's for Christians but it welcomes all faiths and none."
The Better Prepared project is looking to solve the problems the shortage of adult volunteers and the lack of suitable premises in which to meet.
Hannah Kentish, The Scout Association's UK Youth Commissioner, added: "We know Scouting can change lives. So it has to reach those who could benefit the most. That's not because young people are a problem to be fixed, or failure to be corrected. It's because with the right support and the right opportunities; young people can and will thrive.
But let's not be naive. Some communities start from a better place than others. That's why today, I want to make this Promise.
"As an Association, we will support communities in 200 of the poorest wards in the country to establish Scouting for their young people. Led and owned by communities themselves, we'll work in collaboration to ensure that everyone gets the chance to shine. It's a promise to young people across the United Kingdom."
Last year, the Scouts hit the headlines for creating a new promise that members can make when they join.
The new wording saw the removal of God, so that young people with no faith could join without having to make a promise they didn't believe in.