Mrs. Brown's Boys became a runaway success upon its initial broadcast. Every episode aired won its timeslot for RTÉ, with an average viewership of 753,500 in January, 2011. One episode's rating beat that of RTÉ's own ratings giant The Late Late Show, with 856,000 viewers tuning in to watch. However, critics disliked the show. "The whole thing is entirely predicated on viewers finding a man dressed as a foul-mouthed elderly woman intrinsically funny," noted Bernice Harrison in the Irish Times. "If you do, you’re away in a hack (and the viewing figures are astronomical), but if you don’t, and you think that died out with Les Dawson and Dick Emery, then it’s a long half-hour." The Irish Independent said that Mrs Brown's Boys was the type of TV programme that "that makes you vaguely embarrassed to be Irish". The Daily Telegraph's Sam Richards noted that show's comedy has a "rudimentary nature", consisting of "an old-fashioned blend of silly voices and slapstick, played out in front of a live studio audience who collapse into giggles at the mere mention of the word “willy”.
