A shrinking school-age population and a preference for single-sex education are creating uncertainty at some Dunedin secondary schools.
Dunedin city's 10 secondary schools serve a pool of about 7000 students.
Most of the schools have fewer students than 10 years ago and six have rolls of 600 or fewer.
The Ministry of Education says it has no plans to reorganise the schools, but principals say there might be one school too many in the city.
They say co-educational schools have been hardest hit and some expect further roll drops in the next few years.
Declining rolls have already hit some of the city's primary schools, with five in the south of the city set to merge into two schools following a review.
