The number of people treated in hospital in England and Wales after violent incidents fell by 14% in 2012, a Cardiff University study suggests.
Some 267,291 required care - 40,706 fewer than in 2011 - according to a sample of 54 hospital units.
Violence against children fell by nearly a quarter, while among 18-30 year olds - the group consistently at highest risk - the drop was 13%.
Lead researcher Prof Jonathan Shepherd said society "became safer" in 2012.
The survey of accident and emergency and minor injury units has been carried out annually since 2001.
Apart from a 7% increase in 2008, overall levels of serious violence have fallen every year.
Violence towards young children, however, did rise by 20% between January 2009 and December 2010, but the decline shown in the latest figures continues a downward trend which began in 2011.
Among the other findings for 2012 were:
- men are more likely to suffer violence than women - but violence against both genders fell by 14% from 2011
- violence among children aged 10 to 17 fell by 24%, while admissions for under-10s fell by 26%
- Saturday and Sunday were the busiest nights for accident and emergency admissions
- the quietest months were February, April and November
The researchers suggested those months were the quietest because they did not include major holidays like Christmas and Easter, and were outside the summer months when increased numbers of people tend to socialise in cities and town centres.
Prof Shepherd, who is director of the Violence and Society Research Group at Cardiff University, said: "These findings are important because they show that England and Wales became safer, that people can be less worried about being harmed, and that the cost of violence to the NHS and to communities is coming down."
He also said emergency department figures were more accurate than police statistics which tended to suffer from under-reporting.
Reasons for that under-reporting include fear of reprisals, an inability of those injured to identify their attackers, and a lack of faith in the police to take action, he added.