In the course of an investigation on the properties of neopentylpolyol esters, we examined their behavior at high temperatures using two different methods : thermogravimetry with differential thermal analysis (TGA-DTA) and measurement of flash point (ASTM D-93). Thermal behavior of the neopentylpolyol esters was found to be related to the length of acyl chain (C9 : 0, C12 : 0, C14 : 0, C18 : 1, C22 : 1) and nature of the polyol (PE, TMP, NPGHP). We also examined the thermal behavior of the partial esters of pentaerythritol in both, helium and air. The TGA-DTA technique appeared to be a suitable replacement for the flash-point methodology (ASTM D-93), especially for studying the thermal behavior of small amounts of the sample.