Purpose: To compare the long-term efficacy of different systemic therapeutic regimens for patients with noninfectious anterior scleritis to establish guidelines for institution of therapy. Methods: Therapeutic failure of systemic nonsteroidal anti-inflammatory drugs (NSAIDs), systemic steroidal anti-inflammatory drugs, and systemic nonsteroidal immunosuppressive drugs was evaluated in 132 patients with noninfectious anterior scleritis (diffuse, nodular, or necrotizing types). Results: In patients with diffuse scleritis, therapeutic failure for initial regimens occurred in 7% of patients treated with NSAIDs, in 16% of patients treated with steroids, and in 27% of patients treated with immunosuppressive drugs. In patients with nodular scleritis, therapeutic failure for initial regimens occurred in 9% of patients treated with NSAIDs, in 28% of patients treated with steroids, and in 25% of patients treated with immunosuppressive drugs. Addition or substitution of steroids or immunosuppressive drugs as second- or third-line therapies helped control the scleritis. In patients with necrotizing scleritis, therapeutic failure for initial regimens occurred in 100% of patients treated with NSAIDs, in 91% of patients treated with steroids, and in 26% of patients treated with immunosuppressive drugs. Conclusions: In patients with diffuse and nodular scleritis, NSAIDs should be the initial choice; in case of therapeutic failure, steroids should be added or substituted as second-line therapy, tapering and discontinuing them as soon as possible while maintaining remission with continued NSAIDs; in case of therapeutic failure, immunosuppressive drugs should be added or substituted as third-line therapy. In patients with necrotizing scleritis, immunosuppressive drugs should be the initial choice.