Herein disclosed is an improved door window pane guide device which comprises a guide rail having a substantially right-angled side wall which is curled at its leading end portion to form a tubular guide portion, and a carrier unit which is movable along the guide rail together with a window pane secured to the carrier unit. The carrier unit has two plastic sliders which are respectively formed with aligned rectangular grooves into which the tubular guide portion of the guide rail is slidably received upon assembly of the window pane guide device. In order to prevent disengagement of the first and second sliders from the tubular guide portion of the guide rail, an axially extending lug portion is formed on each of the first and second sliders to narrow the entrance portion of the groove, or another slider is arranged between the first and second sliders, which has a right-angled head which slidably engages with the tubular guide portion in a manner to restrict displacement of the first and second sliders in a direction away from the tubular guide portion.