Paul Conner's team finished fourth at the tournament which finished on Saturday. They were the best performing South Island school at the tournament, going on a dream run to make the top four.
Their results were helped in a big way by centre Tom Webley, who averaged more than 30 points a game in eight appearances, including 50 against Tauranga Boys' College.
Cashmere lost its opening game 87-83 to Wellington's St Pat's Silverstream before going on a five-game winning streak.
Canterbury and South Island secondary school champions, Middleton Grange, finished 13th after a 89-77 win against Wellington's St Patrick's College.
Shirley Boys' High School finished 21st after edging-out Christchurch rivals St Andrew's College 72-66.
Christchurch Girls' High School finished eighth at the national secondary schools' girls tournament at Palmerston North.
They lost 62-50 to Manukura after a strong campaign, which saw them reach the quarter-finals.
Rangi Ruru Girls' School finished 16th after a 69-58 loss to Melville High School from Hamilton.
St Andrew's College finished 18th after a 73-33 loss to Rotorua Girls' High School.
Rangiora High School finished 19th after a 50-45 win over Middleton Grange.
Hillmorton High School finished seventh at the Single A boys nationals for smaller schools, beating Catholic Cathedral College 75-66.
Hornby High School finished 12th at their first nationals after a 84-60 loss to Dunedin's Kavanagh College.
The Hornby High School girls' basketball team finished 11th at the Single A girls tournament.