Most A&E departments in England do not identify problem drinkers or offer them long-term help when they seek treatment, a study says.
The impact of 24-hour licences on dangerous drinking is unclear
A survey of all casualty departments, published in Emergency Medicine Journal, found 87% did not ask any questions about alcohol consumption.
This did not appear to affect treatment on the spot, but meant people were not offered sources of long-term help.
Only four of the 191 hospitals formally assessed dangerous drinking.
"Research has found that up to 40% of people attending A&E departments would benefit from help or advice about their drinking," said the study, conducted by Bob Patton of the National Addiction Centre.
"Yet as staff are not using formal screening tools to measure alcohol-related harm, the hazardous drinkers may not get the help they need because they aren't being asked questions about their alcohol use."
Such screening would involve performing blood alcohol tests from those arriving in A&E.
However Action on Addiction, which endorses the report, accepted that these were busy departments where the main priority was providing urgent treatment.
But Chief Executive Lesley King-Lewis added: "By taking the time to formally test patients in this way, we may actually prevent re-attendance."
The Department of Health argues there is only limited evidence as to the value of offering alcohol advice within A&E, but says it is commissioning additional research.
A study last week suggested that alcohol-related A&E admissions in inner-city areas had trebled since the introduction of the new licensing laws in November 2005 that allowed for extended opening.
But the research, which centred on just one London hospital, was dismissed by many as unrepresentative.
Anecdotal evidence from some NHS trusts does not suggest a rise - and there is even evidence of a reduction in alcohol-related admissions in some areas.
However many hospitals, as seen in this latest study, do not record whether an admission is alcohol-related or not.