A self‐consistent theory is presented for particle flows in the flux surface, radial particle fluxes, and the radial electric field in a tokamak. The effects of beam‐impurity momentum exchange, radial transfer of toroidal momentum, and the poloidal variation in density and potential which ensue whenv&fgr;&bartil;vthare treated—the interaction among these effects is nonlinear. Model problem predictions based on the theory indicate enhanced inward impurity transport with strong counterinjection and outward impurity transport with strong coinjection of neutral beams.