Stationary large-scale flow of a collisionless zero-temperature plasma is considered. The relation between the magnetic-field-aligned current i and the properties of the plasma flow is analyzed. We find i= (cB/4&pgr;)[-(V/V) ⋅gradB∥+grad &agr;-(1/B⊥)(E/E) ⋅ B∥+(1-&bgr;)(B∥/B⊥) K cos &agr;>, where V is the velocity of plasma, B∥ and B⊥ are the components of the magnetic field B parallel and perpendicular to V,E is the electric field, &bgr; is the ratio of the kinetic energy density to the magnetic energy density, &agr; is the angle between E and the principal normal to the flow lines, and K is the curvature of the flow lines. The treatment is not restricted by imposition of special boundary conditions.