A fully extendable telescopic drawer guide (10; 10′) for furniture components, such as drawers, work surfaces and the like, that can be extended from the body of an item of furniture, with a guide rail (12) facing the body, a running rail (14) associated with the extendable furniture component, and an intermediate rail (16) arranged between these two rails, wherein rolling elements are provided which are supported in cages (24; 26) and which transfer the load of the extendable furniture component by way of rolling surfaces disposed on the rails, and wherein at least one rotatably supported supporting roller (30) for the running rail is provided on the front end of the intermediate rail. The intermediate rail (16) is implemented as a profile rail which encompasses the region of the guide rail (12) provided with the rolling surfaces and which has on the bottom side an elongated opening for insertion of the support region of the guide rail to be secured to the body wall of an associated item of furniture. The intermediate rail (16) further includes inner rolling surfaces for the rolling elements that face the rolling surfaces of the guide rail (12). The running rail is also formed as a profile rail which also has on the bottom side an elongated opening and encompasses the intermediate rail. Two supporting rollers (30) are supported on the front end of the intermediate rail on axles that protrude horizontally from the opposing lateral profile legs of the intermediate rail (16) perpendicular to the pull-out direction, with the peripheral surfaces of the supporting rollers being supported on rolling surfaces disposed on the interior of the running rail (14) and extending in the pull-out direction.