A vehicle door structure comprises a slide door panel for opening and closing a front region of a rear door opening of a vehicle body and a swing door panel for opening and closing a rear region of the rear door opening in cooperation with the slide door panel, swing door panel lock mechanisms for locking the swing door panel with respect to the vehicle body when the swing door panel is fully closed, and slidability setting mechanisms provided with the vehicle body. Slide rails are provided in upper and lower parts of the vehicle body, while rollers are attached to upper and lower parts of the slide door panel. The slidability setting mechanisms permit the rollers to be introduced to the slide rails only when the swing door panel is locked with respect to the vehicle body.