Rape victims still face a "postcode lottery" over whether their attackers are brought to justice, according to a report published today.
Equality campaigners the Fawcett Society said the latest figures obtained from the Ministry of Justice demonstrate a growing gap in rape conviction rates between police force areas.
Women who report rape are over eleven times more likely to secure a conviction for rape in some areas than others, it said.
In Cleveland, nearly one in five reported rapes led to a conviction for rape in 2007, the report said, but in Dorset, fewer than one in sixty women who reported rape secured a conviction for it.
Rape conviction rates between 2006 and 2007 fell "worryingly" in 16 out of 42 police force areas, the society added.
Some police force areas demonstrated improvement, it found, with Cleveland showing continued improvement since 2004 from 7.75% to 13.2% in 2006 and 18.1% in 2007.
But in many forces performance remained poor, according to the report, with 12 police force areas, more than one in four, with a rape conviction of less than 5% in 2007.
Katherine Rake, director of the Fawcett Society, said: "The appalling figures in most police force areas reveal that women continue to face a postcode lottery when reporting rape to the police.
"Rape should be treated with the same professionalism as other crimes with consistency in initial response to victims and investigation across police areas.
"Co-operation between the police and the CPS is also crucial if the prosecution of rape cases is to improve."
She added: "It is a national scandal that thousands of victims have no access to justice, and frequently face a culture of disbelief and delayed responses which may lead to the loss of vital evidence.
"There is also patchy provision of support services for women who have experienced rape across England and Wales, particularly in rural areas.
"Women deserve support, safety and justice from the criminal justice system and this is not being delivered."
Detective Chief Inspector Alastair Simpson of Cleveland Police, said: "Cleveland Police have worked closely with partners including the Crown Prosecution Service, Primary Care Trust and voluntary sector support agencies to improve our response to victims of rape.
"Within the Force we have given a number of officers specialist training to deal with victims of rape and these officers are always deployed whenever an allegation of rape is received.
"The opening of the Sexual Assault Referral Centre in 2007 has also been a big step forward in improving victim care.
"Cleveland Police take all allegations of rape seriously. Every allegation is treated as a serious crime inquiry and is investigated thoroughly."
Cheshire chief constable Dave Whatton said new guidance has been issued by police and prosecutors to improve the investigation of rape cases.
Mr Whatton, who is the most senior officer in Britain responsible for the investigation of rape, said: "It is unfortunate that in some areas conviction rates are low, but there are many issues to be factored into this.
"Investigations are often complex, particularly on the issue of consent and often because some victims do not want to follow a prosecution route."
A Home Office spokesman said a package of measures was announced in April to improve the police investigation of rape and to provide further support for victims.
"The measures include helping every police force to ensure that all victims are seen by a specially trained officer within an hour of reporting a crime, better training for officers and a cross-Government group to monitor police and CPS performance on rape.
"New guidance for police on investigating and prosecuting rape will be issued shortly and an expert support team will ensure it is delivered consistently around the country.
"Her Majesty's Inspectorate of Constabulary will lead an inspection of forces in 2010-11 to check they are complying with the guidance," he said.