Ireland will be painted green on Thursday as St Patrick’s Day is celebrated at hundreds of events around the country.
Tens of thousands are also expected at Dublin's four-day St Patrick's Festival and its world-famous parade.
Parents have been warned to be extra vigilant over fears children will celebrate the day with alcohol.
Publicans and off-licences have also been told to act responsibly when it comes to selling alcohol to young revellers.
Paul Gilligan, chief executive of the mental health and addiction facility at St Patrick's Hospital, said parents should know their children's plans for the day.
"It is vital that parents are vigilant and aware of the dangers of excessive alcohol use by young people," said Mr Gilligan. "St Patrick's Day is an important day in the social calendar of many young people and it's important that parents keep lines of communication with their teenagers open."
Drinks Industry Group of Ireland chairman Kieran Tobin said while disturbances on St Patrick's Day have reduced in recent years, there was still a clear need for all alcohol retailers to ensure young people are not sold alcohol on the day.
"St Patrick's Day is a major national celebration and a unique opportunity to showcase the best of Ireland to the rest of the world," he said. "Thousands of visitors will come to Ireland to enjoy the unique atmosphere and we must do all in our power to ensure that nothing tarnishes the occasion."
Drinkaware.ie advised people intending to imbibe on St Patrick's Day to start the day with a decent meal and to eat between drinks, avoid large rounds, pace themselves and not to drive the morning after.
Fionnuala Sheehan, of drinkaware.ie, said: "Public drunkenness and excessive drinking had been synonymous with St Patrick's Day celebrations.
"Happily, in 2009 and 2010 we saw very few serious incidents and I would hope that this positive trend of people taking responsibility for their drinking and challenging anti-social behaviour will continue."