Dublin city centre can no longer be deemed clean when compared with other European capitals, the latest Irish Business Against Litter (IBAL) survey has found.
The north inner city has retained its status as a litter blackspot - one of only two in the country.
Carried out in conjunction with heritage body An Taisce, the survey found areas in Dublin, Cork and Limerick remain littered while towns are becoming cleaner.
An Taisce said Dublin city has suffered "a disappointing slip".
"Dublin can no longer be called 'clean'. Less than half the sites surveyed got the top litter grade and even some of the moderately-littered sites could easily become heavily-littered if not addressed," it said.
"It is a pity that the tourists visiting the Guinness Storehouse (the number one fee-paying tourist attraction in the country) are presented with such a littered environment."
Talbot Street, Amiens Street and Kilmainham were also dirty.
"On the positive side, O'Connell Street was in very good order and clearly a close eye is kept on such a busy street," An Taisce said.
It said "little has progressed" in Dublin's north inner city, "despite the negative publicity". Tallaght fared badly as well, but the Dublin Airport environs, Dun Laoghaire and Swords were praised.
In the table of 40 areas surveyed, parts of Dublin, Cork and Limerick occupy the six lowest positions. Cork's Farranree was the other litter blackspot.
Some 75pc of towns and cities were found to be as clean as or cleaner than their European counterparts.
Kilkenny and Cavan were again Ireland's cleanest towns, followed by Killarney, Tramore and Longford. They were among 18 deemed cleaner than the European average.
IBAL's Conor Horgan said: "We're just not seeing the progress in cities that we need. How can we project Ireland as a clean country to visit if large parts of three main cities are littered?"