The present work considers enhancement of mass transport resulting from superimposing an ultrasonically induced convective transport on a diffusional transport. As a result of the nonlinearities in the Navier‐Stokes equation, a time‐dependent secondary flow called acoustic streaming can be produced when an acoustic wave is passed through a medium. Between adjacent vortices or cells, molecular diffusion is the only means of transport; however, within each cell, mass transport is primarily by convection. Increases in the rate of mass transfer of the order of 150% above the normal diffusional flux were found. The theoretical analysis and results presented have application to systems in which ultrasonics may be used to increase mass transfer through membranes (e.g., dialysis), and to increase the efficiency of very active catalytic systems and of solid‐liquid extraction systems.