A fully developed channel flow with periodic transpiration, under the influence of injection and suction, and positive and negative pressure gradients. is a challenging test case for turbulence methods. A direct numerical simulation (DNS) of the flows with weak and strong transpiration is performed. Three low-Reynolds-number turbulence models without wall distance, the stress transport model proposed by Shima, the nonlinear K-epsilon model of Okamoto and Shima and the Launder and Sharma linear K-epsilon model. are tested by using the DNS data obtained. The prediction of the models is generally good near the non-transpired wall, while the stress model reproduces the turbulence quantities near the transpired wall. (C) 2004 Elsevier Ltd. All rights reserved.