More than one in six official inquiries into the most serious cases of child abuse in England are inadequate, the watchdog Ofsted has warned.
In its evaluation of 147 serious case reviews from April 2009 to March 2010, Ofsted found 16% had "weaknesses".
This is better than 2008/9, when 34% of reviews were deemed inadequate.
Serious case reviews are inquiries into the death or serious injury of a child where abuse or neglect is known or suspected to be a factor.
Child protection has been under the spotlight following the failure of social workers in the London borough of Haringey to prevent the abuse and death of 17-month-old Peter Connelly in 2007.
The first review of his death was rejected as unsatisfactory by Ofsted and a second was commissioned. Both were published in full earlier this week.
Ofsted automatically carries out its own review of inquiries into these very serious cases of child abuse.
Inspectors said some reviews had "insufficient consideration" of the child's individual views and needs.
The report said: "Too often the focus on the child was lost; adequate steps were not taken to establish the wishes and feelings of children and young people, and their voice was not sufficiently heard."
Inspectors said the professionals involved had not been challenging enough.
"The statements of parents or others in the family should not have been accepted at face value; individual professionals and agencies should have questioned their own and others' views, decisions and actions; and there were shortcomings in the supervision and intervention by managers."
Ofsted also found eight of the reviews took more than two years to complete - the majority were completed in under a year.
However, the quality of serious case reviews is improving: of the 147 serious case reviews inspected, 62 (42%) were judged to be good, 62 (42%) adequate and 23 (16%) inadequate.
Last year, of the 173 reviews covered, 40 (23%) were judged to be good, 74 (43%) adequate and 59 inadequate (34%).
Chief inspector Christine Gilbert said it was encouraging that more reviews were being judged good, with fewer reviews inadequate.
"The case studies highlight the complexities of the situations which social workers and others are responding to. In undertaking these reviews, agencies have been able to reflect on what happened and learn from their experience," Ms Gilbert said.
Serious case reviews are carried out by bodies known as local safeguarding children's boards, who oversee the work of various agencies involved in child welfare, including social services, education, health services and the police.
Chairman of the Local Government Association's Children and Young People Board, Baroness Shireen Ritchie, said: "Councils are working tirelessly to improve how they identify and protect children at risk from neglect and abuse, and an outside perspective does help.
"When things tragically go wrong they need to be examined. There is important work to be done within the police and NHS as well as at a local government level, and Ofsted also has a role to play in making things better."