Tauranga Boys' College principal Robert Mangan was surprised the figures showed a decrease at the single-sex school.
Mangan said the school's Year 9 intake for the New Year was at 460 students which was up on last year's 410 and the school's roll had so far increased by at least 100 for 2018.
The principal said there was high demand at boys' colleges throughout the country and the benefits were education could be tailored meet the specific gender needs.
Girls could academically outshine boys in co-education schools, Mangan said.
"I think boys respond differently to rules and consequences . . . it is a competitive environment, and the boys enjoy that," he said.
Mangan said New Zealand Council for Educational Research showed boys in single-sex schools on average achieved 10 per cent better academically than boys in co-ed schools.
However, Mangan said overall the quality of secondary school education in the Western Bay of Plenty was high.
"It is good for parents to have the choice from a range of schools including co-ed, single-sex and independent," he said.
Former Tauranga Girls' College principal Pauline Cowens said the decrease in rolls at single-sex secondary schools was due to different subdivisions and growth in Tauranga.
It had nothing to do with students not wanting to attend single-sex schools, she said.
Cowens said Tauranga Girls' College school roll was not declining. "We finished the year last year with a lot of inquiries," she said. "They [Tauranga Girls' College] are looking well ahead on the Ministry's predictions."
Otumoetai College principal Russell Gordon said he attended an all-boys school in his earlier schooling before moving to a co-educational system.
He was also a former teacher at Tauranga Boys' College as well as principal of Mount Maunganui College.
"There are always positives about the environment you are in," Gordon said.
He recommended parents allow their children to decide which school they wished to attend and advised sending teenagers to colleges with their friends.
"If they have a good friendship group, they will achieve well," he said. "If you are with friends who have a positive impact on you develop a healthy competition with them and feel safe and secure at school."
Gordon said a co-educational school replicates society. "Having boys and girls on the same campus tends to create a social setting outside of school . . . it is a positive social outcome for all students."
WHAT ARE THE BENEFITS OF CO-ED AND SINGLE-SEX SCHOOLS?
Tauranga Boys' College student Kale Adair said being at an all-boys school eliminated the social pressure.
"Boys and girls mature differently," Adair said. "In a boys' school, they are able to focus more and ignore the social pressure of interacting with girls."
The 17-year-old said education at a single-sex school was more tailored to the specific gender which encouraged them to be interested in their learning.
Adair said students were more encouraged to participate in extra-curricular activities at a single-sex school.
"I do debating, and I don't think we would have such high participation if it was just girls," he said. "Some activities can be dominated by girls in a co-ed school, so boys are more encouraged to give new things a go."
The Year 13 student said his favourite aspect of Tauranga Boys' College was the school's traditions, including annual sporting fixtures that had been running for 30-40 years.
Former Mount Maunganui College student Dana Kent said a co-ed system gave her the confidence to be able to speak to the opposite sex.
"I struggled to talk to guys a lot, and I always had really good guy friendships at school," she said. "It has helped me learn how to talk to guys and how they act and react."
The 19-year-old said she had always attended a co-ed school and it was "just the norm".
"I'm used to it - it is part of life. I did not find it took away from my education. I used to study with my guy friends, and I helped them pass English," she laughed.
WHAT DO YOU LOVE ABOUT YOUR SCHOOL?
"It has given me the opportunity to develop better connections with other boys which is harder to do at co-ed schools. The cool thing about single-sex schools is the students are patriotic and proud to be from their school. There is also a huge emphasis on respect."
Anaru Palmer, 17. Tauranga Boys' College.
There is no distraction from any girls. There is a brotherhood you can feel and everybody is accepted. In the senior school, we look after the juniors like our little brothers. It is a great environment for a teenage boy to be around. I like to think of Tauranga Boys' College as a man factory, you come in young and rough around the edges and once you leave in Year 13 you leave a fine young man.
Wiremu Leef, 17, Tauranga Boys' College.
There is no distraction from females. There is a brotherhood and students develop a strong friendship bond. The opportunities that are given to us range from arts, sports, technology and more, and there are more opportunities for the boys.
Hunter Eagle, 17, Tauranga Boys' College.
It was the people. I moved down to Tauranga from Auckland at the start of Year 13 and I didn't know anyone. I wasn't coming from another high school in the area, I'd come straight from Auckland. But I made all of my friends in the first two days."
Dana Kent, 19, Mount Maunganui College.
I really love Papamoa College, the open plan works really well for me. I love how the teachers can collaborate with each other and classes can all work together so you're not set in one particular group of people, especially at intermediate and Year 9 level.
Emily Pol, 16, Papamoa College.