A new predictive method based on Partial Order Ranking is introduced in the realm of the QSPR–QSAR Theory using a single descriptor as variable and which is simple enough to perform calculations by hand. Comparisons are made with a model relying on the Least Squares Method subjected to the modeling of the Enthalpy of Formation from Elements exhibed by a set of 51 hydrocarbon molecules by means of a flexible type descriptor. The results achieved with the proposed method are quite satisfactory and its future aplicability seems to be very promising.Facultad de Ciencias ExactasInstituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas