Just 11% of cases relating to abuse of the elderly in one year were passed to prosecutors after being investigated by police, according to official data.
Campaigners claim that even after court cases in which abusers are convicted, most are let off with a caution.
The chief executive of a charity campaigning on the issue told The Times that the UK has "slipped behind" other countries in protecting its older citizens.
To mark World Elder Abuse Awareness Day, the charity Action on Elder Abuse has released data compiled from police forces on how many adult protection cases involving elderly people were passed on the Crown Prosecution Service.
Of the 28,000 cases investigated by police in 2013-14, only 3,317 were sent to prosecutors, it said.
The charity wants new legislation to categorise abuse of old people as an aggravated offence, similar to racially motivated crimes, to reflect the vulnerable nature of victims.
"Elder abuse is a crime and it's long overdue for it to be treated as one," said Gary FitzGerald, chief executive of Action on Elder Abuse.
"The UK has slipped far behind other countries in this regard and we are allowing perpetrators to act with impunity.
"This has to stop. We have to send a clear message to these people that crimes against older people will no longer be tolerated and treated leniently."