Stirling County emerged as the winners of the under-18 trophy last season, beating Selkirk Youth Rugby Club 41-13 at Murrayfield.
Both teams have reached this season’s semi-finals, where Stirling will take on Gala Wanderers, while Selkirk will face last year’s Bowl Champions Boroughmuir.
In this year’s Bowl competition Peebles Colts go head-to-head with Greenock Wanderers while, in the other semi-final, Perthshire face Deeside.
The Under-18 Cup semi-finals will be played on Sunday 22 April unless both teams agree to play the games on the Saturday (21 April) instead.
The Bowl semi-finals are also scheduled to take place on the Sunday.
Scottish Rugby’s head of community rugby, Colin Thomson, said: “The RBS National Youth League Cup is hotting up as it builds towards its climax at Murrayfield.
“It’s great to see some of Scotland top young teams from previous years reaching the semi-finals as well as a host of new teams ready to compete.
“Scottish Rugby wishes all teams involved the best of luck on their road to the final.”
Selkirk Youth v Boroughmuir
Stirling County v Gala Wanderers
Peebles Colts v Greenock Wanderers
Perthshire v Deeside