All students gained literacy (national 91 per cent) and 96.90 per cent gained numeracy (national 89 per cent).
At Level 2 the statistics are no less impressive, he said, with 98.50 per cent gaining a pass, compared with a national pass rate of 87.50 per cent.
Level 3 results trended similarly, he said, with a Rathkeale College pass rate of 81.10 per cent, 25.70 per cent above other boys' schools (55.40 per cent) and the national pass rate of 55.40 per cent.
"It was in the NZQA scholarships that remarkable achievement was to the fore," Mr Harper said.
Year 12 boys Jack Hopman, Gabriel Jacobs Corban and Robert Spite secured scholarships in physics, and Reinhard Schwanecke secured a scholarship in biology, he said.
Overall 11 students from the senior college gained 13 scholarships in six subjects, including an outstanding scholarship awarded to Lauren Taylor in painting.
Other scholarships were awarded to Claudia Green (biology), Sarah Heberley (English), Victoria Leggett (English and geography), Emily Watt (English and history), Campbell Allen-Jones (English), Gabriel Jacobs Corban (physics) and William Warren (painting).
Year 12 and 13 students from St Matthew's Collegiate School, who attend the senior college, also distinguished themselves in all levels of NCEA with a 100 per cent pass rate in Level 2 and a 96.50 per cent at Level 3.
"Once again we were well up on national statistics and also achieved a 100 pass in numeracy and literacy."