Forced convection heat and mass transfer, from a surface made of solid cylinders and its voids that are partially filled with a liquid, are studied numerically using a unit cell model. The predictions are compared with those available from boundary-layer treatment of partially liquid-covered planar surfaces. The results show that as the surface liquid saturation decreases and the Reynolds number increases, a vortex is formed in the partially filled voids. This vortex moves upstream as the Reynolds number increases, and its presence makes the mass transfer characeristics substantially different from those for planar surfaces. The results also show that in limited cases, the ratio of the total mass transfer rate to total heat transfer rate can be approximated by the fraction of the surface area covered by the liquid.