The invention relates to a yieldable rock anchor comprising an anchor element extending along a longitudinal center axis and having a first end, a second end and an outer surface. An anchor plate is attached near the first end of the anchor element, and an anchor head is secured to the first end of the anchor element and adapted to clampingly engage the anchor plate. On its outer surface, the anchor element is provided along at least substantially its entire length with a plurality of ribs. A plurality of sleeves, each sleeve having two opposing ends, for covering some of the plurality of ribs is fixedly arranged on the outer surface of the anchor element such that each of the opposing ends at least substantially sealingly engages the outer surface of the anchor element.