Only 2.5 per cent of the charity's 600,000 members are from BME groups.
Now the charity has received £1.2m from the Big Lottery Fund's Young People's Fund to help girls aged 10 and above from poor backgrounds to overcome socio-economic disadvantage.
The money will be spent on expensive activities such as abseiling and archery, which many potential recruits never get to experience.
"People have thought of us as a Christian, white and middle class organisation," said a spokesman for Girlguiding UK.
"But they are starting to change their perceptions of us because they can see we have been moving out into communities."
The charity has already changed its pledge to include the phrase "my God" rather than "God", to recognise the arrival of different faiths in its membership. It will now focus on places such as Bradford, where 22 per cent of people are from black and minority ethnic groups.
"One of the first projects involves appointing development workers to engage with girls from BME and multi-faith communities in particular," said Jennie Lamb, head of guiding development at the charity. "We want to help these young women participate in challenging activities they would not otherwise undertake."