Asphaltenes are problematic substances for heavy-oil upgrading processes. Recently interesting findings on thermal-cracking kinetics of an asphaltenic residue were reported, but a proposed model which considered parallel reactions for oil + gas and coke formation could not describe the behavior at higher temperatures. It was suggested that in such cases oils participated in secondary coke-forming reactions. Here we reexamine the data and give the expression for the oil + gas yield as a function of asphaltene conversion or residence time, which describes the data well. Further, we show that an empirical relation for coke formation and asphaltene conversion gives a reasonable description of the kinetics and prediction of the cracking behavior at high conversion level or long residence time, and that this method is much simpler. The maximum yield of oil + gas and the conversion level corresponding to the maximum yield can also be predicted easily. Further, our proposed approach is not dependent on assumed reaction orders of cracking. Crown Copyright