In this paper B-spline curve fitting and sweep surface generation are used for the geometric design of involute gears. Tooth profiles are described by a B-spline formulation based on interpolating data points with first and second derivative constrains. Tooth surfaces are generated by sweeping the B-spline profiles along specified trajectories. This representation scheme enables tooth shapes to be interactively controlled by manipulating control polygons and sweep trajectories. A CAD-CAE integration allows the analysis of contact and structural three-dimensional problems for various geometric configurations. In the paper the methodology is applied to the geometric design of involute pinions of face gear drives.