Participation-based figures released to schools showed the South Dunedin decile 6 secondary school achieved a 93.2% pass rate in NCEA level 1, the highest in the country.
It achieved 90.8% in NCEA level 2, the second highest in the country, and 82.4% in NCEA level 3, the third highest in the country.
Overall, the school was the highest-ranked boys' state school in New Zealand.
Wellington College was ranked second, and Shirley Boys' High School third.
Otago Boys' High School was ranked ninth, Waitaki Boys' High School was ranked 15th and Southland Boys' High School was ranked 18th of the 23 state boys' schools nationwide.
King's High School principal Dan Reddiex said the results reflected a significant transformation in the school's culture.
"The high expectations of staff, a strong values programme, excellent tracking systems and accountability for student performance are all key drivers behind the outstanding student outcomes."
While Waitaki Boys' High School rector Paul Jackson was pleased with his school's results, he was quick to point out the statistics did not reflect the large number of year 11 pupils who achieved NCEA level 2, when they were only expected to achieve level 1.
"We had 30 year 11 boys sit level 2 and achieved it last year."
He believed some schools in New Zealand doctored their results to make them look more favourable, by not allowing pupils to enrol in NCEA if they were unlikely to pass.
Mr Reddiex said it was not a practice carried out by King's High School.
Otago Boys' High School rector Clive Rennie said statistics should not be taken at face value, with variables behind the figures.
"Our three levels of qualification can be earned through a combination of assessment methods," he said.
"Unit standards and achievement standards can be combined in a variety of ways. Achievement standards culminate in a higher education pathway."
While the participation-based statistics showed a higher percentage of King's High School pupils had achieved NCEA qualifications than Otago Boys' High School, 65.5% of his pupils had gained university entrance, as opposed to King's High School's rate of 54.1%, Mr Rennie said.
"A true measure of student qualification is the pathways they are able to pursue upon leaving school," he said.
