A heating and emulsifying device (10), particularly for heating and optionally emulsifying air and milk in milk-based products and having the capability to regulate the air-flow and the milk-flow jointly and proportionally, comprises an emulsification chamber (12) having an opening (14) for the delivery of the product and a steam-inlet duct (20) which opens into the emulsification chamber (12). A milk-inlet duct (28) and an air-inlet duct (30) communicate with the steam inlet duct (20), the air and the milk being drawn in by the partial vacuum created by the flow of steam. An air-flow regulator (38) and a milk-flow regulator (40) are operatively associated with the air-inlet duct (30) and with the milk-inlet duct (28), respectively, the air-flow and milk-flow regulators being structurally connected and being suitable for varying the respective flow-rates in proportion with one another and the emulsion/milk ratio in the final product, without affecting its temperature.