Outcome assessment of rheumatic diseases has a significant role in evaluating the effect of various therapies in clinical studies and in the treatment of these patients in daily practice. Outcome assessment in rheumatic disorders is based on the evaluation of disease activity, quality of life, disability, and mortality caused by the disease. Behçet's disease (BD) is a multisystem inflammatory condition that can cause damage to multiple organs. Damage assessment, along with assessment of BD activity, are two necessary and complementary components of BD outcome measures, based on Outcome Measures in Rheumatology. In clinical trials of BD, outcome assessment has been based on disease activity measures, which do not measure damage severity. In this review, we considered three damage indices that have recently been introduced to assess BD-related injury, including vasculitis damage index (VDI), Behçet's syndrome overall damage index (BODI), and Behçet's disease damage index (BDI).