Twenty-six pubs may be prosecuted for breaches of the public health regulations and licensing laws following the easing of the Covid-19 restrictions last week.
Pubs that served food, as well as restaurants, were reopened when the restrictions were lifted.
Most of the pubs facing prosecution were found not to be serving food along with alcohol.
Gardaí say they carried out 6,830 checks on almost 3,000 licensed premises all over the country last weekend and the vast majority were found to be in compliance with the regulations.
However, some publicans had to be warned about breaches before complying.
Files will be sent to the Director of Public Prosecutions, who will decide how many of the 26 cases are to be brought before the courts.
Deputy Garda Commissioner John Twomey said gardaí are concerned that a minority are potentially putting people's health at risk.
The checks were carried out on pubs and restaurants from 7pm last Friday to midnight on Sunday as part of Operation Navigation, which was set up to ensure licensed premises were complying with the public health regulations to stop the spread of the coronavirus.
Gardaí said that during these visits they continued the graduated policing response of engaging, educating and encouraging before, as a last resort, moving to enforce the law.
There were 2,785 licensed premises found to be open all over the country and the vast majority were in compliance.
However, gardaí say in some pubs they found customers drinking alcohol, but no evidence of food also being consumed and no evidence of receipts to show that food had been sold.
Under the health regulations alcohol can only be sold to a person at the same time as they order a substantial meal.
The penalty for a breach can be a fine of up to €2,500 and/or up to six months in prison.
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Gardaí also said they found pubs allowing large groups at the one table, with little to no social distancing, no advisory signage, and no Covid-19 contact tracing recorded.
Some pubs complied with the regulations after being warned by gardaí, but 26 have now been identified for possible prosecution.
Gardaí said they are concerned that a minority are potentially putting the health of their customers and staff and everyone they come into contact with at risk of contracting the coronavirus.
Deputy Commissioner Twomey said gardaí are sending a clear message to such publicans that they will be opposing their liquor licence renewal applications in September unless they come into compliance.
The Government said those pubs operating in breach of the Covid-19 health and safety regulations are putting the health of their customers and staff and everyone they come into contact with at risk of getting the virus.
At this morning's Government Briefing, the Assistant Secretary at the Department of the Taoiseach, Liz Canavan, said the best thing the public can do is to support the businesses who are trying to do the right thing and to avoid those which are not.
She said people should "support compliance and those businesses who want to stay open, who want to keep employing their staff and who want to save their business".