MDM2 inhibitors class of anti-neoplastic drugs has been evolve after the successful discovery of the nutlins and other potent inhibitors. MDM2 inhibitors can specifically target the tumour cells in the body, by selectively reactivating the inhibited p53 function in the tumour cells.None of the compound of this class has been entered into the market till date, all are under clinical trials. Hence, various researcher classifies them according to their p53 topology mimetic property and as per their peptide type or non-peptide type.Synthetic peptide type of inhibitors can mimic the conformation of p53 helix. Whereas, small organic molecule (non-peptide) type of MDM2 inhibitors have been further subdivided as Non α-helix mimetics (small molecule inhibitors) and α-helix mimetics. In a line with synthetic inhibitors, many potent MDM2 inhibitors are derived from the natural origin (marine, fungus). Therefore, keeping in a view of all these characteristics, here we have classified them as per best of our knowledge.