The victims' commissioner, Baroness Newlove, has launched a series of reviews to scrutinise the work of criminal justice agencies.
Lady Newlove said she was challenging the government to "take action" to help people cope with the "haunting aftermath" of crime.
The government said she was bringing about "positive change".
'Real difference'
Baroness Newlove, who campaigned for victims' rights following the murder of her husband Gary in 2007, was made victims' commissioner in 2012.
Launching the reviews in her annual report on Tuesday, she said: "Victims deserve the very best possible support to get them through the haunting aftermath of crime.
"If they are not getting this - their concerns need to be taken seriously and improvements need to be made as a result."
She said she would be looking at good and bad practice across the different services, adding: "With the findings of each review, I will be challenging the government and other agencies to take action and make a real difference to victims and their families."
The reviews will assess compliance with the Victims' Code, which was revised in October 2013 and includes the right of victims to personally address offenders in court to explain how a crime has affected them.
The first review, conducted by a three-person team, will start in the autumn, also looking at handling of complaints and the use of restorative justice.
Adam Pemberton, assistant chief executive at Victim Support, said: "We welcome the victims' commissioner's decision to make monitoring the code a priority because we know from supporting hundreds of thousands of victims and witnesses every year how important it is that they are treated with dignity and respect."
The issue was key to maintaining public confidence in the criminal justice system, Mr Pemberton added.
Damian Green, the victims' minister, welcomed Baroness Newlove's report.
He said: "Her position is instrumental in holding to account the positive change brought about by this government, such as the greatly improved Victims' Code which gives those impacted by crime a much greater voice.
"This report shows the value the Victims' Commissioner has already brought and provides an excellent basis for delivering further improvements."

The 19-year-old netted on her debut for Arsenal Ladies in 2013 and scored 22 goals in her first full season with the north London club.
Humphrey is the Belles sixth signing following their promotion to Women's Super League One.
"I want to get some more experience and help the team do as well as we can," she told the club website.

The note was sent in 1960 to the family of Stan Laurel's childhood friend Margaret Miller, who went on to marry the star's school friend.
The signed and dated letter thanks Mrs Miller for her belated Christmas card calendar and talks about his "many happy memories" of Tynemouth Pavilion.
Newcastle auctioneer Anderson and Garland said the item could create a "bit of a frenzy" among bidders.
Mrs Miller's daughter, also called Margaret, found the letter in her brother's belongings when she moved house.
The 88-year-old from Hexham, said: "My father and Stan Laurel were at school together in Tynemouth in the 1890s.
"Stan's family lived in North Shields and my father's family knew them quite well.
"My parents were going to the United States on holiday and hoped to meet up with him.
"I don't think they did and I imagine that's why my mother sent the calendar to him because he didn't get to see it."
Laurel was born in Ulverston and later emigrated to the US where he found fame in Hollywood.
Before emigrating, he spent much of his life in the north-east of England, going to school in Bishop Auckland, County Durham, and Tynemouth.
Anderson and Garland auctioneer Fred Wyrley-Birch said: "There is such a lovely story behind this letter, which is likely to add to the value of the piece when it goes under the hammer.
"We expect people interested in Stan Laurel's North East connections, as well as autograph collectors, to be among the bidders. It may well create a bit of a frenzy."
It goes to auction on Tuesday and is expected to fetch between Â£300 and Â£500.
The way crime victims are treated by the police and courts in England and Wales is to be examined.
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Doncaster Rovers Belles have signed Arsenal Ladies' teenage midfielder Carla Humphrey on loan.
[NEXT_CONCEPT]
A letter from Cumbrian-born comedian Stan Laurel is to be auctioned.