This work explores the feasibility of using the Newton Thermal Analysis method (NTA) as an alternative technique for quantitative determination of the relative volume fractions of the microconstituents formed during solidification of three hypereutectic Pb-Sn alloys. The results suggest that NTA has a good potential as a quantitative microstructure analysis tool. However, it is required to further improve the method in order to match the microstructure predictions with the experimental measurements obtained by quantitative metallography.