The chain wants to be seen as health conscious and ethical, selling nutritious meals and fair-trade produce.
It is attempting to reach out to urban, professional, affluent men and women in their late 20s and 30s.
'Slug and Lettuce wants to attract consumers who like to eat meals at affordable prices in stylish places - not binge-drinkers,' said Storm director Amanda Williams.
The agency will be expected to thrash out the position of Slug and Lettuce in the debate on smoking in pubs and raise the profile of the chain in the media around significant calendar dates such as Christmas, Valentine's Day and No Smoking Day 2006.
Storm, which won the account in a two-way shootout with three-year incumbent ZPR, will also work on SFI brands the Litten Tree, Siesta Havana and Bar Med on an ad hoc basis.