A sliding door fitting for an item of furniture having a (furniture) body, which, in a preferred embodiment, is designed as open toward at least one front side and closed on multiple other sides, thus at least on a ceiling wall and/or a floor wall, wherein at least one closure element (7, 8), in particular a sliding door (7, 8), is arranged so it is movable relative to the body and relative to a further closure element (7, 8), in particular a further sliding door (7, 8), in each case using the sliding door fitting, on the outside in front of the open front side of the furniture body, wherein the closure element (7, 8) and the further closure element (7, 8) preferably lie in a common plane in the closed position, wherein the sliding door fitting has the following: a. at least one or more carriage arrangements (10, 11) which each have first and second outer guide carriages (12a, 12b) and associated first and second inner guide carriages (18a, 18b), b. wherein the outer guide carriages (12a, 12b) are displaceable parallel to the main movement direction of the at least one closure element (7, 8), and wherein the first and second inner guide carriages (18a, 18b), which are movable in relation to the outer guide carriages (12a, 12b), are arranged on the first and second outer guide carriages (12a, 12b), c. for which purpose slide units (S1 and S2) are formed between the first and second outer and inner guide carriages (12a, 18a or 12b, 18b), d. wherein one or more curve parts (40, 41) having a control curve contour (27a, 27b) is/are fixed on the rail device as separate part(s), e. wherein to control the slider element movement of the slide devices (S1, S2) of the first and second outer and inner guide carriages (12a, 18a or 12b, 18b), a control roller, which is guided in a corresponding control contour (27a, 27b, 28) of the rail device, is arranged only on one of the inner guide carriages (18a, 18b) or on an element of each carriage arrangement (10, 11) fixed on one of these inner guide carriages (18a, 18b), characterized in that f. a control part having a control contour is fixed on the rail device as a separate part, g. wherein a sufficiently synchronized movement of the other inner guide carriage (18a, 18b) is implemented without control roller by a multiple joint lever kinematics unit, h. wherein a connecting element such as a strut or a connecting plate connects the first inner guide carriage to the second inner guide carriage as part of the multiple joint lever kinematics unit and booms (32a and 32b) are formed on the connecting element, i. wherein furthermore the first inner guide carriage has a first linkage point as part of the multiple joint lever kinematics unit, on which a further boom is linked, on which the sliding door (7, 8) is fastened, and the second outer guide carriage has a second linkage point and a third linkage point is arranged on the boom, j. wherein furthermore a connecting lever is pivot-articulated in each case on the linkage point G2 (pivot bearing) on the second outer guide carriage and on the boom on the linkage point G3 (pivot bearing) as part of the multiple joint lever kinematics unit. a. at least one or more carriage arrangements (10, 11) which each have first and second outer guide carriages (12a, 12b) and associated first and second inner guide carriages (18a, 18b), b. wherein the outer guide carriages (12a, 12b) are displaceable parallel to the main movement direction of the at least one closure element (7, 8), and wherein the first and second inner guide carriages (18a, 18b), which are movable in relation to the outer guide carriages (12a, 12b), are arranged on the first and second outer guide carriages (12a, 12b), c. for which purpose slide units (S1 and S2) are formed between the first and second outer and inner guide carriages (12a, 18a or 12b, 18b), d. wherein one or more curve parts (40, 41) having a control curve contour (27a, 27b) is/are fixed on the rail device as separate part(s), e. wherein to control the slider element movement of the slide devices (S1, S2) of the first and second outer and inner guide carriages (12a, 18a or 12b, 18b), a control roller, which is guided in a corresponding control contour (27a, 27b, 28) of the rail device, is arranged only on one of the inner guide carriages (18a, 18b) or on an element of each carriage arrangement (10, 11) fixed on one of these inner guide carriages (18a, 18b), characterized in that f. a control part having a control contour is fixed on the rail device as a separate part, g. wherein a sufficiently synchronized movement of the other inner guide carriage (18a, 18b) is implemented without control roller by a multiple joint lever kinematics unit, h. wherein a connecting element such as a strut or a connecting plate connects the first inner guide carriage to the second inner guide carriage as part of the multiple joint lever kinematics unit and booms (32a and 32b) are formed on the connecting element, i. wherein furthermore the first inner guide carriage has a first linkage point as part of the multiple joint lever kinematics unit, on which a further boom is linked, on which the sliding door (7, 8) is fastened, and the second outer guide carriage has a second linkage point and a third linkage point is arranged on the boom, j. wherein furthermore a connecting lever is pivot-articulated in each case on the linkage point G2 (pivot bearing) on the second outer guide carriage and on the boom on the linkage point G3 (pivot bearing) as part of the multiple joint lever kinematics unit.