Killarney has dropped down to 22nd position in the latest Irish Business Against Litter survey, despite retaining its clean status.
Both Killarney and Tralee are classed as Clean to European Norms by IBAL.
Tralee retained its spot at number 14 on the list, of the 40 surveyed.
However, Killarney now sits at 22nd position; it was placed 13th in the last survey in January.
Nationally, two-thirds of the towns and cities surveyed were found to be clean.