Staff should also monitor tables where a lot of people are coming and going and pay particular attention to toilets, where drugs are often consumed.
The document, Guidelines Regarding Drug Dealing on or in the Vicinity of Licensed Premises, was published yesterday by Assistant Commissioner for the Dublin Metropolitan Region, Al McHugh.
The guidelines, an action plan under the National Drugs Strategy 2001-2008, were drawn up in conjunction with the Licensed Vintners Association, the Vintners Federation of Ireland, the Irish Nightclub Industry Association and the Irish Hotels Federation.
Some 14,000 copies are being distributed to members of those organisations.
The report advises pubs and nightclubs to consider the introduction of searches of persons a condition of entry.
However, the document said only gardaí were legally entitled to search people and that if a person refused a request from staff, a search could not take place.
Mr McHugh said that under Operation Nightcap, a special garda investigation into drug dealing in clubs and pubs, two licensed premises had been closed down in Dublin in recent years.
John Mansworth of the Vintners Federation of Ireland said the “age profile” of publicans was such that many weren’t aware what the symptoms of drug use were.