Rosebank built up to full strength but in 1944 it closed to serve as a Juniorate for five years. While still retaining registration as a secondary school, Rosebank entered another stage of its history when it re-opened as a boarding and day College in 1951 with 334 pupils, offering academic, cultural and vocational subjects as an alternative to straight academic courses.


Gradually the College built up to a Leaving Certificate School until in 1966, in the process of regionalisation in Sydney and the phasing in of the Wyndham Scheme, it reverted to a Form 4 School. In this context, the school celebrated its Centenary in ‘67.