In March there were an estimated 341,360 private sector enterprises, up 9.9% on the previous year and the largest total since 2000, the first year for which such figures are available.
Despite the economic crisis, the estimated number of business has increased every year since 2006.
Enterprise Minister Fergus Ewing said the rising number is "encouraging, especially in the current economic climate".
He said: "The rise has been driven by start-up enterprises, a sign that Scots are confident enough to go out and make the most of the opportunities available."
Only 2,250 of the businesses employ 250 or more people, 0.7% of the total number of firms.
Almost all businesses in Scotland are classed as small, with 98.3% of them employing up to 49 people, and 1.1% of businesses are medium-sized, employing between 50 and 249 people.
The success of small and medium-sized businesses is "integral to the success of our overall economy", Mr Ewing said.
"That is why the Scottish Government is committed to maintaining Scotland as the most competitive place to do business and providing the most generous package of reliefs, which includes the Small Business Bonus Scheme, available anywhere in the UK. When considered together, these reliefs are worth over £500 million a year."