Ministry chief executive officer, Aeau Christopher Hazelman said there were a number of reasons behind the departures, including finding work with the seasonal work schemes in Australia and New Zealand, and better paid jobs in other ministries.
RNZ Pacific reports some teachers were taking up theological studies.
The ministry has recently reached out to qualified teachers working in other ministries to work part-time at teaching.
It is also looking at the use of volunteers as an option to tackle the critical shortage of teachers.
