The flow generated due to the motion of flat plate is an important problem in fluid mechanics, since it gives insight into the unsteady boundary layer generation. The entropy analysis of such how problems can provide enlightening information on the viscous dissipation in the fluid how. In the present study, an impulsively started Couette dow is studied, where a flow between two parallel plates is moved impulsively by moving the lower plate from rest to a finite velocity in the half-space y > 0. Development of velocity and entropy profiles, at different time scales, has been numerically obtained; the development of total entropy with time, in the space between the plates, has been determined. It is found that entropy generation in the space between the plates is more considerable at initial times of motion than at later times. Copyright (C) 2001 John Wiley & Sons, Ltd.