Thermal behaviours of two parents calix[4]arene (1-2) and three azoealix[4]arene derivatives (3-5) containing upper rim functionalized groups such as n-butyl, phenylazo and heterocyclic thiazol were investigated by means of thermogravimetry (TG), differential thermal analysis (DTA) and differential thermogravimetry (DTG). The thermal decomposition points and amounts of volatile pyrolysis products were determined in nitrogen and air atmosphere using TG, DTA and DTG curves. In the present study, the thermal analysis of azocalix[4]arenes demonstrated that the stability of the calix[4]arene depends on substituted groups and their position in the calix[4]arene structure. (C) 2004 Elsevier B.V. All rights reserved.