Most of the analytical and theoretical developments presented on the buckling and large displacement behavior of curved beams involve the in plane-of-curvature behavior (buckling of arches). Very little information of practical value on the influence of curvature on the lateral torsional behavior of horizontally curved I-girders loaded normal to the plane of curvature has been presented. Data on the behavior of singly-symmetric and non-prismatic sections, and data on the effects of lateral restraints provided by cross-frames and diaphragms is practically nonexistent. For these reasons, the finite element method was used to define the effects of curvature on the lateral-torsional buckling behavior of curved I-girders. A set of numerical "test" girders of varying dimensions and support conditions were used. The buckling and large displacement behavior is demonstrated for girders with and without lateral restraints that simulate the effects of cross frames or diaphragms. Analytical results of curved beams with supports provided only at the ends demonstrate a gradual reduction in elastic critical load with increase in curvature. However, it is demonstrated that the elastic critical load for global buckling of curved beams that have intermediate lateral restraints actually increases with addition of curvature due to a "snap-through" transition of stiffness.