A device for heating and emulsifying liquids, in particular drinks, which is unusually capable of generating a dense and creamy foam, comprises a steam-emitting member with which a hollow body can be associated. The steam-emitting member comprises a spout positioned along the hollow body at a height such as to be above the level of the liquid to be emulsified. Inserted coaxially inside the hollow body is a duct which defines a first passage and a second passage. A region for communication between the first passage, the second passage and a third passage for air, which is placed in communication with a groove formed in the inner surface of the hollow body, is provided between the steam-emitting member and the duct. The steam-emitting member comprises two annular projections provided with sectors which have different transverse dimensions and which are offset relative to one another and define a labyrinthine path.