Five per cent of charities in Scotland bring in 91 per cent of the sector's income, according to new figures from the Office of the Scottish Charity Regulator.
There are 31 charities for every 10,000 people in Scotland, and the most common charitable purpose is the advancement of education.
A new report, Scottish Charities 2005, provides an overview of the size, charitable purposes and geographical location of organisations in the sector, based on annual returns from 18,000 bodies.
According to the statistics, 40 per cent of all charities in Scotland are located in four local authority areas - Edinburgh, Glasgow, Fife and Highland.
Jane Ryder, chief executive at the OSCR, said: "This is the first report of its kind, and this type of information is essential in the development of a modern regulatory framework. It is intended to inform charities, local authorities and other stakeholders about the sector."
The Scottish Council of Voluntary Organisations said the figures echoed its own research on the sector since 1996.
"Small charities are the lifeblood of the Scottish sector and make up much of its diversity - but this is being threatened by over-regulation," said a spokesman.