There had been reports of people stealing things at 5.30am.
Staff believe people conduct "drive-bys" to see what is available. Household goods that can be resold are being targeted, including small appliances, furniture and crockery.
"We suspect it is professional thieves that sell it on. We are tracking an item on TradeMe. Things have turned up at the Sunday market in Masterton," Mrs Jones said.
Centre management will improve security, she said.
"We are going to be changing the front doorway to make it more secure."
CCTV is also being considered and security guards could be used as a last resort, she said.
If the thefts continue, the existence of the business could be threatened.
"We are losing money through what people are removing. We can't make the money back again," centre projects manager Jonathan Hooker said.
"The only way the business can stay viable is through donations and volunteers."
The Salvation Army has also been targeted and Lieutenant Daryn Bishop met with centre members yesterday morning to discuss the problem.
"Both businesses are only here to help the community," Mr Hooker said.
The police have been informed.
If anyone has information about the thefts, they are asked to call the Wairarapa Resource Centre or the police.