In this study of the effect of wall conduction on laminar free convection between asymmetrically heated vertical plates, an implicit finite difference scheme is used to solve the governing equations. The governing independent parameters are identified to be Prandtl number (Pr), Grashof number (Or), ratio of thermal conductivity of the solid to air (K), wall thickness to channel width ratio (t/B), channel height to width ratio (L/B) and the asymmetric heating parameter (γH). The effect of wall conduction on free convective flow of air under asymmetrically heated conditions (γH = 1.0, 0.5, and 0) is discussed. Calculations are made for K = 1 and 10, t/B = 0.1 and 0.5, Gr = 10-104, and L/B = 1 and 5. The maximum increase in mass flow rate of air for symmetric heating due to wall conduction is 30%. The maximum decrease in average Nusselt number due to wall conduction is 22%. Wall conduction effects are more significant for low Gr flows than for high Gr flows.