The cyclic shift of a language , defined as =, is an operation known to preserve both regularity and context-freeness. Its descriptional complexity has been addressed in Maslov's pioneering paper on the state complexity of regular language operations [Soviet Math. Dokl. 11 (1970) 1373-1375], where a high lower bound for partial DFAs using a growing alphabet was given. We improve this result by using a fixed 4-letter alphabet, obtaining a lower bound (n-1)! 2, which shows that the state complexity of cyclic shift is for alphabets with at least 4 letters. For 2- and 3-letter alphabets, we prove state complexity. We also establish a tight 2n lower bound for the nondeterministic state complexity of this operation using a binary alphabet.