The assembly has banned smoking in enclosed public places and workplaces from the summer of 2007 and wants the Welsh to be aware of the new law, which achieved Royal Assent last week.
"We will be promoting the health implications of second-hand smoke, which is responsible for 400 deaths each year in Wales," said Cambrensis chairman Rhodri Ellis Owen.
The brief targets consumers and businesses: primary audiences being adult smokers and SMEs; secondary audiences being non-smokers and large companies. The campaign will use case studies of companies and organisations such as sports clubs, revealing how banning smoking from their premises has not harmed business, said Owen.
The brief also involves advising on a 12-week consultation with stakeholders such as local health boards on how the ban should be implemented. For example, whether it should include smoking on stage at the theatre or in private members' clubs and hotel rooms.
Consolidated and Cambrensis scooped the account after pitching against Geronimo Communications and Grayling. The two agencies already work in tandem on other accounts such as the Energy Savings Trust.