The demolition of the old Cornwall St School buildings began this week after the school was targeted by vandals.
Contractors Bruce Buchanan began demolishing the disused school's old bike shed and bus shelter on Monday.
The school was built in the 1950s and closed in 2004 as part of a Ministry of Education review that saw seven local schools closed.
The Masterton site has not been used since and has become a target for vandals.
"The buildings have been targeted by vandals and it was decided to remove them in the interests of keeping the site safe," said a Ministry of Education spokesman.