Thousands of pounds worth of damage was caused to St Patrick’s Church, in Owton Manor, Hartlepool, including about a dozen broken windows.
Church managers said vandals targeted the church over four successive nights.
They broke and damaged stained and coloured glass windows and left areas inside covered in masonry and debris.
David Frank, chair of St Patrick’s Community Council, which looks after the church, said: “All week we have been cleaning up after them.
"It’s very upsetting for parishioners.”
The first damage was caused on the night of Tuesday, April 5, and was discovered the following day when David went to open the church for a mass service.
He said: “We tidied up for mass. But when we came the next day they had come back after we had gone and made an awful lot of damage."
The vandalism has been reported to the police who are appealing for information.
David said the vandals returned again on Thursday, April 7, and Friday, April 8.
It is believed a group was responsible.
“It is a number of individuals who for some reason have nothing better to do than damage other people’s property,” added David.
It comes at one of the most important times of the year for parishioners with Easter and Holy Week.
David said: “We have just celebrated our 60th anniversary of the church.
"We’re really part of the community and the community do support us. It just takes these individuals to spoil things.
"We are concerned that they might come back and do further damage.”
The cost of the damage is estimated to be at least £5,000.
A small window pane broken last year has only recently been repaired due to the insurance process.
"It’s specialist work,” said David. “There’s a lot of work involved in repairing them.”
Cleveland Police said: “Police received a report of criminal damage caused at St Patrick’s RC Church which is believed to have happened between 7.15pm on Tuesday, 5th April, and 10.30am on Wednesday, 6th April.”
Any witnesses or anyone with information is asked to contact Cleveland Police on 101, quoting incident number 056402, or Crimestoppers anonymously on 0800 555111, or online at www.crimestoppers-uk.org.