Edward Walsh (52) was involved in a car crash on his way home, and gardai discovered he was almost three times over the legal driving limit.
Walsh apologised to the judge for his behaviour, saying he did not know what came over him.
A judge ordered him to complete an alcohol awareness course and said she was banning him from driving for three years.
Walsh, of Glenamuck Cottages, Carrickmines, admitted before Dun Laoghaire District Court to a charge of drunken driving.
The incident took place on Brennanstown Road, Cabinteely on January 20 last.
Garda Sergeant Peadar McCann said Walsh was involved in a car crash, and when gardai spoke to him they found he was unsteady on his feet and there was a smell of alcohol from his breath.
He was taken to the garda station and breathalysed. He gave a reading of 93mg of alcohol per 100ml of breath -- almost three times over the legal driving limit.
Defence solicitor Ronnie Lynam said Walsh is unemployed and hasn't worked for four years.
Walsh told the court he was sober for six years, but he started drinking again after he visited his sister in the hospice. He said he is sober again.
The defendant told Judge Ann Ryan that he doesn't attend AA as it "made me worse", and he prefers to deal with his drink problem in his own way.
Judge Ryan said Walsh might benefit from doing an alcohol awareness course.
She adjourned the matter to a date in June, saying that if Walsh completes the course she will ban him for three years and fine him €200.