"Tell him I said he's a muppet. He should be in the theatre -- he's not a critic," Corrigan told the Herald.
"I am deadly serious -- he's a muppet," Corrigan insisted.
Corrigan took a pop at fellow Michelin star chef McGrath just days after he described his dishes using words of faint praise such as "simple and nice".
McGrath, who is often described in some quarters as being the country's most controversial chef, was recently awarded one of the Irish food industry's highest accolades.
McGrath, who runs Mint in Ranelagh, won his first Michelin star earlier this year.
After appearing in a controversial RTE documentary, McGrath was widely criticised for his treatment of staff in Mint. But it appears that Richard Corrigan hasn't too much time to worry about outspoken McGrath's underwhelming descriptions of his food.
Most of Corrigan's time is taken up running his flagship Bentley's London restaurant which is a favourite of celebrities over there.
This isn't the first time Dylan McGrath has attracted the ire of his fellow chefs -- and his appearance in his RTE documentary appears to have made him few friends.
Last March, top chef Patrick Guilbaud lashed out at his young rival, branding him "sad" for his shouting and swearing outbursts at staff.
The French chef, whose Dublin restaurant was the first to achieve two Michelin stars, scoffed at McGrath's recent outing on an RTE show entitled Pressure Cooker.
In the programme Mr McGrath was featured repeatedly shouting at staff.
When asked about his rival's antics on Conversations with Eamon Dunphy today, Mr Guilbaud said: "I think it's very sad. It's fantastic to see that we have a lot of new restaurants in Dublin. It's great to see young people getting that success. But do they need to shout to make something good?" he asks.
"My job is to attract people to the restaurant business and I don't think by shouting and swearing at people you can do so... you might for a while but they won't stay. It's not necessary," Mr Guilbaud said.
Mr Guilbaud (56) first came to Ireland in 1981 and he explains that since then his kitchen has never resembled those shown on television: "If you go in the kitchen at Restaurant Patrick Guilbaud, it's very quiet. The chef speaks. It's a tough business, a tough environment, but you have to work as a team.
"I can't understand why you have to shout at people to make a team work, maybe I am missing something but I don't see it."