A method is presented for qualitative assessment of nanoclay dispersion in a polymeric matrix, which is based on the effect of nanoclay dispersion on the thermal stability of polymer/nanoclay (PNC) systems. The method offers a fast, inexpensive macroscopic evaluation of nanoclay dispersion, which can be used for direct comparison of nanoclay dispersion in PNC samples. Using experimental design, it is also possible to discover material or process conditions that lead to desirable nanoclay dispersion. Furthermore, this method can be employed for confirmation purposes in support of other nanoclay dispersion assessment techniques. We proved this finding by means of six different independently obtained pieces of information on the quality of nanoclay dispersion in the samples, which are x-ray diffraction, atomic force microscopy, transmission electron microscopy, gas permeability, as well as mechanical and rheological measurements. We believe this method could be employed to study nanoclay dispersion in thermoset matrices as well, for which utilizing other techniques may be either unfeasible or difficult; therefore, this method could present an alternative for assessing nanoclay dispersion in this class of polymeric materials.