Lithuanian Government Vice Chancellor Deividas Matulionis says the campaign will run on national and regional media channels, including news websites, TV, press and social networks.
The Foreign Ministry is also launching the campaign through diplomatic missions.
Information about the referendum will also be available on government and ministerial websites.
The awareness campaign has cost the government 230,000 euros.
In the May 12 referendum, voters will be asked to decide whether to allow dual citizenship to citizens of countries meeting "Euroatlantic integration criteria", with a list of such countries to be set by a law.
Currently, people who left Lithuania after it regained independence in 1990 cannot hold dual citizenship, apart from a few exceptions. That provision can only be amended by referendum.
An opinion poll commissioned by the government showed last week that around two-thirds of those polled intended to vote in May's dual citizenship referendum.