Scottish Rugby says it has surpassed its target to increase the number of people playing the sport by more than 50% - two years ahead of schedule.
And it puts the success down to a steady recovery of participants in state school rugby.
"We've specifically targeted the early secondary S1-S3 age groups - the habit forming years," it said.
There are now 25,000 under-18 players taking part in regular rugby compared to 15,000 just four years ago.
The number of schools regularly playing the game has risen from 184 in 2008 to more than 240 in 2010.
And Scotland's governing body says it indicates success for a scheme that rewards and supports school staff who give up their time to take extra-curricular rugby - and a network of 75 club development officers.
In 2006, Scottish Rugby had set a target of increasing participation from 24,500 to 38,000 by 2012 and, ahead of its annual meeting on Saturday, it has published total playing figures of more than 38,500.
But head of community rugby Colin Thomson, himself a former PE teacher, said: "This recent growth remains on a fragile footing and will take up to five years to convert into adult participation, providing that children continue to get the opportunity to play rugby year on year.
"If we're serious about sport moving towards the 2014 Commonwealth Games in Glasgow, we should be serious about state school sport - because, if we don't do it in our state schools, we won't get anywhere.
"It's essential that all children are offered the opportunity to attend extra-curricular and after-school sports clubs throughout their school years.
"To do so, we need more support and recognition for the teachers taking after-school sport in order to build a healthy and active culture within every state school."