Abstract: The present invention relates to a device for diffusing a fragrant product in a water stream. The device includes a main body with an inlet and an outlet for the water stream, interconnected by a channel for the passage of the stream. The main body is configured to be mounted on a water circuit with the inlet and the outlet arranged between an outlet of the water stream distribution system and a shower pipe inlet, respectively, so as to allow the water stream to circulate through the passage channel of the distribution system towards the shower pipe. The main body includes a receptacle configured to receive and position a diffuser body in the passage channel for the fragrant product to be diffused.