Founded in 1987, JHA owns and operates 78 dental practices across the UK.
Dublin-based Cybercom, which has increased its presence in the UK over the past 12 months, triumphed against eight UK agencies to land the account.
Its scope includes digital planning, the redevelopment of the JHA website, organic and paid search marketing, digital PR, online advertising and a social media strategy.
Jonathan Forrest, managing director of Cybercom, said: "Winning the James Hull Associates account is significant.
"We celebrated 10 years in business this year and a key element of our strategy is to grow our business beyond Ireland.
"Already 20% of our business comes from the UK, with clients that include Coca-Cola, Open University and Hearst Digital."
This article was first published on brandrepublic.com