Last year, 154 people were arrested for drink-driving over Paddy's Day weekend.
One person lost their life and three others were injured.
The Road Safety Authority is urging people to make arrangements to get home safely if they are going out tonight or tomorrow.
CEO of the organisation, Moyagh Murdoch, says this weekend is a dangerous period on our roads.
Were you drinking last night? Make sure that you aren't over the limit this morning. pic.twitter.com/p5Slx1Zsg5— RSA Ireland (@RSAIreland) March 16, 2019
"We are urging people to take care out there," said Ms Murdoch.
"St Patrick's weekend is, like many bank holiday weekends, a dangerous period, and last year we had three people seriously injured over the weekend and one person killed."
The RSA is urging people not to walk home from the pub this St Patrick's weekend.
Almost half of pedestrians killed on Irish roads have consumed alcohol.
Seven pedestrians have been killed on our roads so far this year.
People are being advised that it may take longer to sober up if you drink at home as opposed to in the pub.
According to the RSA, people tend to pour larger measures at home than they would be served in a bar.
It takes the average person an hour to get rid of the effects of a small glass of wine or half a pint.
"When you're drinking at home your measures are not standard pub measures so you may mis-calculate the amount that you have consumed," said Ms Murdoch.
"So you must be aware of that and give your body time to process that alcohol and do not risk driving the morning after if you have had a heavy night the night before."
#StPatricksDay is about a lot more that alcohol. So let's challenge the stereotype. Let's consider a more mindful approach to drinking alcohol throughout the celebrations. Let's reflect who we are as a nation today. https://t.co/kBaaPf7TVF pic.twitter.com/PheWp3iWuL— Drinkaware IRL (@Drinkaware_ie) March 15, 2019
Meanwhile, the HSE is expressing concern over the amount of alcohol and other drugs that will be consumed during St Patrick's weekend events.
It is advising people not to use drugs, but if they do, do not mix substances and do not 'binge'.
The HSE is worried people are searching online for information on club drugs such as speed, ecstasy, ketamine, cocaine, GHB and 'poppers'.
— HSE Ireland (@HSELive) March 15, 2019
HSE National Clinical Lead for addiction services Dr Eamon Keenan has this advice if you notice your friend on drugs: "Look out for your friends, if you see your friend running into trouble talk to them, make sure they are not alone, don't let them go off into a corner and get sick.
Additionally, Water Safety Ireland are warning that water and alcohol do not mix.
They are asking people to be very careful around coasts and inland waterways this St Patrick's weekend.
Deputy CEO, Roger Sweeney, says water temperatures are still very cold and hypothermia can add to the risks of falling into water or being trapped by incoming tides.
"Keep children away from the water's edge, never drink alcohol when you are planning aquatic activities and remember to always wear a life jacket when you are on or near water and that goes for anglers as well who are angling close to the coast," said Mr Sweeney.
"Be aware of unexpected waves that may come along as well."