Three-dimensional slow viscous flow due to the broadside motion of a thin plate parallel to an infinite plane is considered with the assumption that the gap between the plate and the plane wall is much smaller than the size of the plate. Using the method of matched asymptotic expansions, asymptotic expressions for the force and torque exerted by the fluid are obtained. (C) 2001 Published by The Japan Society of Fluid Mechanics and Elsevier Science B.V. All rights reserved.