Only three police forces are well prepared to tackle honour-based violence, a landmark report has found.
Inspectors said urgent improvement is needed in the understanding, investigation, and recording of offences in the category, which includes forced marriage and female genital mutilation (FGM).
The presence of honour-based crime in the UK has been exposed by shocking cases such as the killings of Shafilea Ahmed and Banaz Mahmod in 2003 and 2006 respectively.
But in the first inquiry of its kind watchdogs concluded that few forces have have taken all necessary steps to make sure they fully understand the nature and scale of the issue.
They found some officers are concerned about being seen as "culturally insensitive" when dealing with honour-based violence (HBV), with one victim saying police are "too scared of coming across as racist".
Another woman who raised the alarm about death threats from her ex-husband was allegedly told: "He is not killing you, you are still around."
The report by Her Majesty's Inspectorate of Constabulary (HMIC) found that all but three of the 43 forces in England and Wales are "prepared to some extent" to protect and support victims of the HBV effectively.
However, only three were assessed as being prepared across all four categories examined: leadership; awareness and understanding; protection and enforcement; and prevention.
Only four received approval over their capacity to investigate incidents.
HBV covers practices used mainly to control the behaviour of women and girls within families or other social groups to protect "supposed cultural and religious beliefs, values and social norms in the name of 'honour'," HMIC said, adding that incidents are not unique to any culture, community or area.
Chief Inspector Sir Thomas Winsor said: "This report is one of the most important ever produced by HMIC, as these are crimes of unique seriousness, involving a degree of vulnerability which is absent in almost every other case, with the exception of the abuse, neglect and sexual exploitation of children."
The report raised concerns about the identification, recording and flagging of cases on police computer systems. Some forces had very limited or no capability at all to flag cases.
"Victims may be placed at risk if the context of their records is not clear, and the risk to other vulnerable individuals related to them may not be realised," the report warned.
Officers and staff did not always recognise "indicators" of HBV, the report said. In some instances they were said to have spoken to "precisely the wrong type of person" such as family or community members who may be involved in the reported case.
Frontline staff must have sufficient knowledge to implement the "one chance rule" - meaning they may only have one opportunity to speak to a victim and potentially save their life, the report said.
But it added: "The findings of this inspection show that this is not currently the case."
Inspector of Constabulary Wendy Williams said: "Honour-based violence is being suffered on a daily basis by blameless citizens across all areas and communities.
"Although initial responses by the police are good, only a small number of forces are well-prepared for the complexity that honour-based violence cases can pose.
"It is clear that the police service has some way to go before the public can be confident that honour-based violence is properly understood by the police, and that potential and actual victims are adequately and effectively protected."
Keith Vaz, chairman of the Home Affairs Select Committee said: "This report clearly shows that Police Forces still do not have this problem under control, or fully understand it. 'Honour-based' violence remains in the shadows."
Commander Mak Chishty, of the National Police Chiefs' Council, said: "We are working to develop a more consistent approach to policing in this area, particularly in the early identification of victims, potential offenders and protecting vulnerable people by managing risk.
"We have always placed the victim at the heart of our response to this kind of abuse. During the last 12 months we have developed a new strategy to ensure that the police service is doing all it can to eradicate all forms of honour-based abuse."
An NSPCC spokesman said: "We know that young girls who have been subjected to cruelty such as FGM and forced marriage will only report it if they feel confident - which is why it is so important we ensure the police and other professionals are equipped to deal with these complex forms of abuse."