In this study, the burning profiles of twenty-five lignite samples originating from different parts of Turkey were obtained using a thermogravimetry technique (TGA). In the light of these profiles, the effect of the mineral matter content on the combustion behaviour of the lignite samples is discussed. The DTG curves of the lignite samples before and after mineral matter removal were obtained from TG applications under the same working conditions. Plots of the weight loss differences between the original and demineralized lignite samples against temperature were derived from TG applications. The relationship of the weight loss (calculated on a dry, ash-free basis) differences between the original and demineralized lignite samples at 1273 K with the mineral species was investigated. All correlations were developed by means of regression analysis. Experiments have shown that the mineral matter content of the lignite samples plays an important role in determining the combustion characteristics. Data indicate that the effects of the mineral species on the combustion characteristics are more pronounced at higher temperatures.