A hybrid numerical scheme is presented for use on two-dimensional, incompressible flows of low viscosity. The scheme divides the domain D into two regions, D 1 and D 2, and the Navier-Stakes equations are solved by different methods in each. In the region D 1, which is composed of a narrow strip adjoining the boundary, the grid-free vortex method is used. An alternating direction implicit (ADI) method is used in the interior domain D 2 which contains that part of D that lies a short distance away from the boundary. The hybrid method allows vorticity exchange between the two regions by partially merging and realigning them. Boundary conditions for the vorticity are automatically treated by the vortex method. Favorable numerical results have been obtained for the problem of recirculating flow in a square cavity for Reynolds numbers of 400 and 1000.