Nelson College has been given top marks in its latest monitoring report by the Education Review Office.
The single-sex boys school will next be reviewed in four to five years, putting it in the top bracket of ERO review reporting.
Just 13 percent of schools reviewed by the ERO were placed in the four to five year review category in the 2015/2016 year, with the rest set to be monitored more frequently.
Nelson College Headmaster Gary O'Shea said he was delighted with the result.
He said the school was last reviewed in 2012 and continues to work hard to improve the learning environment, especially for Maori students, former refugee pupils, and high-needs learners.
"We've done better [over the last four years] at identifying those kids and then supporting them culturally, or with learning resources, staff, and so on."
The ERO found the school to be performing well across all areas, including in NCEA pass rates and school culture.
The report, issued on Tuesday, said Nelson College has an inclusive environment that keeps students engaged and well-equipped for future endeavours.
The ERO has cited the strong NCEA results by Maori students in 2014 and 2015 as a testament to the value placed on te reo and tikanga Maori.
Leavers' data for 2014 and 2015 shows between 70 and 80 per cent of Maori students achieved at least Level 2 in NCEA.
Two thirds of Year 13 Maori students in 2015 achieved a Level 3 certificate.
O'Shea said more than just the academic results, he was pleased the ERO recognised the school as being a place where the boys feel valued, and the school climate is healthy.
"Kids like being here, they feel respected, they feel the programmes are suited to them, and they feel listened to ... there's a strong sense of belonging."
O'Shea said Nelson College has around 50 former refugee students, and about 14 percent of the roll is Maori.
He said the cultural context improved when they built a whare about five years ago, and they also have a Maori head boy and deputy head boy.