New research by Goldsmiths College at the University of London found 70,000 women who volunteer in parishes are now into their 80s and 90s.
Author of the analysis, Dr Abby Day was quoted by the Daily Mail as saying: "The prognosis for the Church of England is grave.
"While elderly laywomen have never been given a formal voice or fully acknowledged by the Church, they are the heart, soul and driving organisational force in parishes everywhere.
"Their loss will be catastrophic."
In her new book, The Religious Lives of Older Laywomen, Dr Day found this army of volunteers also play a fundamental role in furnishing, cleaning, and raising money for Anglican churches.
The research warns the passion for volunteering among the so-called Generation A (parents of the 1960s baby boomers) is not being passed onto their children and grandchildren.
Dr Day concluded that younger generations are more likely to shun practical acts of service and express their beliefs in less practical ways, such as activism.
She said 'Generation A' is "the last generation whose values are centred on nation, family and God."
A Church of England spokesperson said: "Thousands of our churches are busy throughout the week serving the community through the provision of services from foodbanks to post offices, pre-school clubs to social events for the elderly, combating the growing loneliness epidemic.
"Renewal and Reform, the church's programme for growth, is reversing the recent decline in numbers attending church and removing barriers to mission and effective ministry, enabling young and old to live out their calling.
"The dedication of thousands of men and women of all ages is inspiring and with over 120, 000 baptisms each year the Church is being renewed and reinvigorated in each generation."