A numerical study is conducted to examine the heat transfer characteristics of fully developed laminar flow in a parallel-plate channel with an internal, longitudinal, corrugated fin. The objective of the study is to determine the effects of the thermal contact resistance at the channel wall-fin interfaces and the asymmetric heating of the channel walls on the distributions of the local channel and fin surface temperature and heat flux. The solutions of the momentum and energy equations are obtained by using a control-volume-based finite difference algorithm. Local and regionally averaged surface temperatures and heat fluxes are determined for two fin pitches, two fin thicknesses, and two values of the fin/fluid thermal conductivity ratio. The overall heat transfer in the finned channel is compared with that in a corresponding plain parallel-plate channel. The results of the study are applicable to the design of internally-finned channels in compact heat exchangers.