A numerical simulation is performed to study the influence of an oscillating cylinder on the heat transfer from heated blocks in a channel flow. An arbitrary Lagrangian-Eulerian kinematics description method is adopted to describe the flow and thermal fields. A penalty consistent finite element formulation is applied to solve the governing equations. The effects of Reynolds number, oscillating amplitude and oscillating frequency on the heat transfer characteristics of the heated wall are examined. The results show that the heat transfer from heated blocks is enhanced remarkably as the oscillating frequency of the cylinder is in lock-in region. (C) 2003 Elsevier Ltd. All rights reserved.