Diabetes mellitus is a serious global health problem and taking its place as one of the main threats to human health in the 21 st century. The National Diabetes Information Clearinghouse & World Health Organization shows above 90% of the diabetic population fall under type 2 diabetes mellitus category. The treatment generally prescribed for type 2 diabetes mellitus has been a combination of diet, exercise and current therapeutic agents Due to their adverse effects and side effects, most of these treatments are considered to be unsatisfactory in terms of preventio n of complications and preservation of quality of life. The current therapeutic agents containing thiazolidine-2,4-diones or glitazones are shown better treatment on type 2 diabetes mellitus via acting on peroxisome proliferator-activated receptor-gamma (PPAR-γ). From these glitazones, troglitazone and rosiglitazone are withdrawn from markets. Pioglitazone and lobeglitazone are used in market. Ciglitazone, englitazone, darglitazone, KRP-297, rivoglitazone and CLX-921 are discontinued in various clinical trials. Mitoglitazone, netoglitazone and balaglitazone are present in various phases of clinical trials. Furthermore, based on various literature surveys, we are studied in details structure activity relationships of various glitazones.