In this paper, laminar forced convection flow of Al₂O₃-water nanofluid in triangular-corrugated channel is numerically studied. The governing mass, momentum and energy equations in body-fitted coordinates are solved using finite volume method. Reynolds number and nanoparticle volume fractions are in the ranges of 100–800 and 0–5%, respectively. The effect of Reynolds number, nanoparticles volume fraction and nanoparticles diameter on the flow and thermal characteristics are examined. The results indicate that the Nusselt number increased as Reynolds number and nanopartiles volume fraction increased but the pressure drop increased as well. Also, Nusselt number increased as the nanoparticle diameter decreased, while there is no effect of nanoparticle diameter on the pressure drop.