An electrodeless low-pressure discharge lamp which comprises a discharge vessel, a means for exciting discharge, an UV-to-visible-converting layer and an UV reflecting layer. The discharge vessel encloses a gas-tight discharge cavity containing an ionizable fill. The discharge vessel has a light-transmitting bulb portion and a reentrant tube protruding into the discharge cavity, and the bulb portion and the reentrant tube each exhibit a surface facing to the discharge cavity. The means for exciting discharge is arranged at least partially in the reentrant tube. The UV-to-visible-converting layer is applied only to the surface of the bulb portion, while the UV reflecting layer is applied to the surface of the reentrant tube.