A lack of affordable housing means many more people in England's rural areas are becoming homeless, the Countryside Agency says.
Migration from towns to rural areas has pushed up house prices
The proportion of homeless households in remote rural districts rose by almost 30% in two years, its State of the Countryside Report 2004 found.
More people are moving from towns into rural England, causing house prices to rise faster, the agency says.
Homelessness charities warned of a "devastating impact" on rural families.
Countryside Agency chairwoman Pam Warhurst said increasing migration to England's countryside was having an "unintended impact".
She told BBC Radio 4's Today Programme: "There is an increase in the rural population which is putting pressure on housing stock and a number of other areas.
"There are people living in the country that have some disadvantage because of that."
She urged the government to develop policies to ensure changes in rural areas were sustainable.
"Those who exercise their choice to move can reduce the choices of the less well-off in rural areas and affect the character of our countryside," she said.
"The most damaging effect is the increase in house prices, making fewer and fewer homes affordable for local families and increasing homelessness in remoter areas."
The report warns homelessness is "commonly perceived as an urban problem, largely as a result of the invisibility and underestimation of homelessness in rural areas".
Homelessness charity Crisis warned the phenomenon of "sofa-surfing", where homeless people move from one friend's house to another, meant many local authorities were unaware how many vulnerable people needed help.
Research by the Countryside Agency and Crisis in Craven, North Yorkshire, found only half the homeless people staying with friends and family had applied for local authority help.
Half were under 25 and one in five aged under 19.
They also had a "relatively high incidence" of personal issues including time spent in care, mental health problems, involvement with the criminal justice system and alcohol and drug misuse, Crisis said.
Nationwide, the problem was exacerbated by a lack of social housing, the report said, accounting for only 13% of homes in rural areas compared to 22% in towns.
Adam Sampson, director of Shelter, urged the government to reform the right-to-buy scheme so local authorities could protect stocks of social housing in rural areas.
He said: "Many households are trapped in overcrowded or unsuitable housing, or even forced into emergency accommodation through homelessness."
Shadow environment secretary Tim Yeo said the report "identifies some of the problems which have been made worse by Labour's discrimination against rural communities".
"Local economies are being hurt by the loss of rural services and... older people are becoming
increasingly isolated by the loss of accessible local facilities," he added.
A rural land survey in 2003 showed almost half those buying a house with land attached in England were non-farmers.
Since 2002, house prices have risen faster in rural areas than in urban ones, with affordability an issue across England.
More than a third of rural dwellers would have to spend over 50% of their household income each month on mortgage repayments, the report said.
But despite this the 14m people living in rural England - almost three in 10 of the population - saw the countryside as "a good place to live" overall.
HOUSE AFFORDABILITY AND HOMELESSNESS
Affordability index based on calculations involving mortgage payments for an average house and average household incomes.
Rural and urban definitions from government and Countryside Agency: rural settlements under 10,000 people; urban over 10,000.