The restaurant chain saw pitches from five different agencies before handing the three-month brief to Shine.
Pizza Express' head of external comms Jane Botros said: 'We were looking for a PR campaign that targets the foodie opinion-formers with our exciting launch, and Shine's pitch really delivered this.'
The agency has been asked to deliver a high-impact national media relations campaign for the pizza chain. The launch of the new menu is due to take place on 1 October.
Shine's senior account director Natalie Turner will lead the account. The key target titles are The Observer Food Monthly, The Daily Telegraph, The Times and The Guardian Weekend. It will also target other consumer titles as well as online and broadcast media, seeking specifically to connect with the ABC1 demographic.
Pizza Express, which is now part of the Gondola Group, has used agency support on a project basis for menu changes in the past. Most recently it used Frank PR and Stuart Higgins Communications.
Shine takes on the brief amid tough times for pizza and pasta restaurants, as the economic downturn leads people to eat out less. But recent Mintel research still values the market at more than £1.4bn.
Pizza Express is the third-largest pizza and pasta chain in the UK by number of outlets. It trails the takeaway-oriented market leaders Pizza Hut and Domino's Pizza.