Purpose: thermal behavior of some antidiabetic drugs such as pioglitazone hydrochloride (PTZ), rosiglitazone maleate (RGZ), glibenclamide (GBD) and glimepiride (GMP) has been studied. Methods: Thermogravimetric analysis (TGA), derivative thermogravimetry (DTG) and differential thermal analysis (DTA) techniques were used to study the thermal behavior of the drugs under investigation.Results: thermal analysis technique was used to obtain quality control parameters such as melting point 193.13 oC, 122.42 oC, 173.75 oC and 208 oC for PTZ, RGZ, GBD and GMP, respectively. The values of melting point of gave satisfactory results in comparison to that obtained by using the official method. Non-isothermal methods were employed to determine the activation energy values of the first stage of thermal decomposition. Comparison of the activation energy values suggests the following sequence of thermal stability: GMP>GBD>RGZ>PTZ.Conclusion: The results obtained are useful for the identification of these compounds and permitted interpretations concerning their thermal decomposition. thermal stability of pharmaceutical compounds can be studied and compared by using thermal analysis techniques.