Abstract. We study codeterminants in the q-Schur algebra S q (n, r) and prove that the standard ones form a basis of S q (n, r), using a quantized version of the Désarménien matrix. We find elements of the form F S 1 λ E T in Lusztig's modified enveloping algebra of gl(n), which, up to powers of q, map to the basis of standard codeterminants, where F S ∈ U − and E T ∈ U + are explicitly given products of root vectors, depending on Young tableaux S and T .