This study numerically investigates the two-dimensional forced convection in a channel containing short multi-boards mounted with heat generating blocks. The computation domain covers the all boards, and the region from the channel inlet to the location far away from the trailing edges of the boards. The flow and thermal characteristics are rigorously examined for the cases with various block height H-b, block spacing S-b, heat conductivity ratio of board to fluid K-pf, heat conductivity ratio of block to fluid K-bf, and Reynolds number Re. Results show that, owing to the effects of thermal interaction among the sub-streams of fluid through the conducting boards, the differences in transfer characteristics of the blocks mounted on different boards are rather significant. Comparing the maximum temperatures of the blocks on different boards, the maximum difference is up to 61% when 0 <= K-pf <= 200, 100 <= K-bf <= 200, 0.05 <= H-b <= 0.15, 0.5 <= S-b <= 2.5 and 200 <= Re <= 1000. In addition the maximum deviation in the average Nusselt numbers (Nu) over bar of the blocks on different boards is about 51%. (C) 2007 Elsevier Ltd. All rights reserved.