It is important to measure and evaluate related parameters to classify diabetic foot ulcers, since it will enable us to decide the treatment modality, predict the prognosis, compare the treatment results and carry out clinical studies. The methods of measurement and classification should be clear, repeatable, practical and based on objective criteria, to be validated and widely used. The parameters and factors measured and used for classification are size, depth and localization of the ulcer, characteristics of wound bed, perfusion of foot, existence of infection and neuropathy. There are some complex systems for measuring wound size besides several simple methods which is easy and practical to use. Several systems that assess different parameters for classifying diabetic foot ulcers have been in use so far. While the Wagner system that assesses ulcer depths and gangrene to classify diabetic foot has been well known and most used one, the Classification System of University of Texas San Antonio (UTSA) has been in use by adding ischemia and infection to assessment list; PEDIS system included neuropathy, S(AS) SAD system added wound area, and SINBAD system simplified the previous system and added localization of the ulcer into assessment parameters. These systems standardized the data collected in the diabetic foot centers and used in some clinical studies.