The prize for this award is a trip to Dublin in May for Hennessy and his partner Sue Burnett, which will include attending a VIP hosting at the Guinness Brewery and going to the Bushmill's Distillery.
He said the bar having the best Guinness was something Hennessy's had known for a long time, and was something told to them regularly by customers - particularly customers from the United Kingdom.
Hennessy said there were three reasons why he had always said they had great Guinness.
The first was that you had to sell a lot of it, and Hennessy's was in the top five per cent of New Zealand for sales.
He said everything must also be kept totally clean in the bar's systems - "We've invested a lot of time and money into this".
The third reason was because of the refrigeration system at the end of the bar which meant the Guinness was always fresh.
Along with this award, Hennessy's Irish Bar Rotorua has also made the final eight in the worldwide Irish Pub Global Awards.
Hennessy said there were 24,000 online nominations for the award.
"We just couldn't believe we had made the final eight in the world.
"We want to thank the staff as well as all their customers, both local and visiting, who make Hennessy's such a success."
