Around one in nine listed places of worship in England is in a poor or very bad condition, according to a survey published today.
Research by English Heritage has shown that 11% of places of worship including churches and synagogues are potentially at risk because of their poor or very bad physical condition - but 89% are in good or "fair" condition.
The conservation body said the survey results were better than had been feared by some and were a "huge testament" to the hard work and altruism of congregations.
Chief executive Dr Simon Thurley urged places of worship to take a "stitch in time" approach to repairs.
He said: "The current climate of increased unemployment, low interest rates and reduced returns on invested capital make fundraising a greater challenge than ever.
"Alongside this, some congregations are finding the responsibility harder to bear unless their whole community comes together to support its most historic and iconic building.
"I urge everyone who cares about their local church, chapel, synagogue or other place of worship to lend a hand.
"Don't be put off by what might seem like an impossible challenge - the key is to do small things really well.
"Finding somewhere to serve cups of tea might achieve just as much as a major building project.
"Clearing gutters could save the need for a whole new roof or renewing damp walls at a cost of thousands of pounds."
The survey of 2,215 buildings showed rural listed places of worship were more likely to be at risk than urban ones - 13%, or around one in eight - compared to 9% or one in 11 in urban areas.
But in places such as Tower Hamlets and Hackney, in London, where all listed places of worship were surveyed, 21% were in poor or very bad condition.
A similar survey in inner city Birmingham - excluding the central business district - indicated that 28% of listed places of worship were at risk.
The survey also found 11 of the 32 listed synagogues were found to be in poor or very bad condition.
Congregations surveyed said they wanted more information on getting permission to make changes, funding for installing tea points and toilets and advice on finding potential sources of funding.
English Heritage said grants of £40 million a year help, but an estimated £925 million of outstanding repairs need to be done over the next five years with the majority paid through voluntary giving and organised by congregations.
John Penrose, minister for tourism and heritage, said: "England's cathedrals, churches and other places of worship are central to most people's views of our heritage.
"I am delighted that they're overwhelmingly in fine shape. It's a testament not only to public funding but, more importantly, to the dedication and hard work of thousands of volunteers who give up their time to keep them in good order."
Crispin Truman, chief executive of the Churches Conservation Trust - the charity for historic churches no longer used for regular worship - said: "The report is helpful in producing the first register of places of worship at risk.
"However, between 20 to 30 churches are closed each year in England alone.
"These buildings are of significant national and community importance.
"Alternative and diverse community-led approaches, ranging from conservation to shared use, must be the priority to keep these buildings open and in use."
The Church of England said fundraising and hard work by its congregations was keeping thousands of historic buildings in good condition, open to the public for worship and, increasingly, a growing range of community activities.
A statement from the Church of England said it maintained more of the country's architectural heritage than any other organisation - some 12,300 listed buildings.
Anne Sloman, chairwoman of the Church Buildings Council, said: "Churches are regularly inspected between the five-yearly architectural surveys they are required to have by the Church of England and the vast majority - 90% - are in good condition.
"Congregations and volunteers make an enormous effort to raise the funds and do the work that keeps so many listed church buildings in good condition on behalf of the nation and the communities they serve.
"The additional funds provided through English Heritage and the current VAT refund scheme ensure that all that effort is encouraged and supported so that potential problems, that could cost hundreds of thousands of pounds if nothing is done, are addressed at an early stage."
She added: "We would also echo English Heritage's call on the Government to continue the Listed Places of Worship Scheme beyond March 2011 so that the maintenance of so much historic architecture is not held back by the extra costs of VAT."