The council won the Communicators of the Year award for, 'excellent communications across the board', according to judges.
The council was shortlisted in six categories, more than any other council, and picked up the best internal communications prize and a highly commended certificate in the best civic newspaper section, won by the London Borough of Islington.
East Riding head of communications Simon Taylor, who picked up the award, said: 'We've looked at how work can be improved as well as funded.'
He added that he hopes the comms team, can be self-funding within two years, largely through commercial and advertising deals.
Deals already secured include a link up with local paper the Hull Daily Mail. That deal was struck in a 'gentleman's agreement', according to Taylor, whereby the council pledged not to go through with a planned increase in frequency of its monthly newspaper, East Riding News.
For the Communicator of the Year award, judges' special mentions went to Essex County Council and Newcastle and Gateshead councils.
Newcastle and Gateshead scooped two awards: Best Campaign for promotion of their joint bid to become Europe's Capital of Culture in 2008 and the most successful partnership award.
Essex gained five short listings and won the Best Media Relations award.
It also gained a highly commended certificate for its internal comms work.
Other winners were: Dudley, which won the PRWeek-sponsored PR on a Shoestring award, Cardiff won the Best Publication or Leaflet award, Slough took the Best Consultation award and Devon won the E-media prize.