Fluid flow and heat transfer in two-dimensional wavy channels of uniform cross-sectional area were analyzed numerically for constant-property Laminar flow. The channel walls were maintained at constant temperature. Streamwise pertodic geometry caused the flow and heat transfer to repeat periodically far downstream of the channel entrance. Computations were performed for different Reynolds numbers and geometric parameters. Prandtl number was kept constant (0.707). The whole solution domain was divided into five regions, and different coordinates were used for each region. The periodic boundary conditions were implemememted by mutual repiacements of field values at the two end regions. It was found that both Nussel: number and friction factor were greatly affected by Reynolds number and two geometric parameters.