The deposition of supramicrometer-sized aerosol particles on the internal walls of transport tubes and inlets is of considerable importance in sampling of radioactive aerosols. In most previous studies, the effects of inertial and gravitational forces have been considered; however, the lift force on particles in shear flows is also of consequence. Here, in the analysis of particle depositional effects, we show there is a characteristic parameter, PI, which can be used in evaluating the lift effect. Comparison of the lift and drag forces are made to illustrate the impact of the lift force on particle deposition. An analytical solution is obtained for particle trajectories in sheared laminar flows. A stability condition is obtained for the equations which describe the particle trajectories. Also, the asymptotic position of an aerosol particle is given in terms of a deflection stopping distance. The results are valid for laminar flow situations in which there is no streamline curvature. © 1992.