A semi-trailer landing gear, in particular for trailers of utility vehicles, wherein the semi-trailer landing gear extends along a longitudinal axis and comprises an outer supporting tube and/or a transmission box, wherein the outer supporting tube and/or the transmission box comprise an outer wall, and wherein the outer wall comprises a fastening side, wherein at least one fastening portion is formed in the region of the fastening side, and wherein the fastening portion is designed to fasten and/or to arrange the semi-trailer landing gear on a further element, in particular a trailer, characterized in that a transmission is arranged in the transmission box, which transmission is coupled to a spindle drive, in that the fastening portion comprises at least one fastening element, and/or in that the fastening portion comprises at least one arrangement portion for arranging and/or fastening the at least one fastening element, and in that a ratio of a distance between the fastening elements and/or the arrangement portions of two fastening portions transversely to the longitudinal axis of the semi-trailer landing gear to a width of the transmission box or the outer supporting tube in this region is less than 1.