The disclosure relates to image-based characterization of implanted medical leads used for electrical stimulation therapy. Characterization of implanted leads may include determination of lead configuration and lead orientation. The lead characterization techniques may make use of two-dimensional (2D) lead imaging in combination with known three-dimensional (3D) lead configuration data for various lead types. Lead characteristics determined from 2D lead imaging may be compared to lead dimensions calculated from known 3D lead characteristics to characterize implanted leads in terms of lead configuration and orientation. The lead characterization may be used to automatically determine or verify led configuration and orientation, and to aid in programming electrical stimulation therapy parameters.