The evaluation of the applicability of thermoanalytical methods to the assessment of the quality of refined rapeseed oils was performed. Density, refractive index, and saponification, iodine and acid numbers of rapeseed oils were determined as part of the study. By correlating the data obtained with the temperatures of initial, final and successive mass losses determined from the thermogravimetric curves, strong relations were observed. The possibility of a practical utilization of regression equations for the assessment of the quality of refined rapeseed oils was indicated. The results of principal component analysis indicate that thermogravimetric techniques are very useful in defining the quality of rapeseed oils compared with chemical analyses.