The Diels–Alder addition reactions of a series of acenes (anthracene, 9,10-dimenthylanthracene, tetracene and pentacene) to C60 fullerene are next to equilibrium reactions and were analyzed using a classic chemical thermodynamics approach using group increment calculations. In the case of the C60/anthracene adducts and C60/dimethylanthracene adducts the calculations results were compared with experimental thermochemical data and found in fair agreement. The calculations showed a progressive reactivity of the acenes with C60 following the sequence pentacene ≥ tetracene >> anthracene. The thermochemical calculations show also that both naphthalene and 1,2,3,4-tetramethylnaphalene are not reactive with C60 and no adducts are expected for these two acenes. The temperature field of existence of the C60/acenes adducts where disclosed with the thermochemical calculations and compared with experimental data. In general the C60/acenes adducts are stable at low or moderately high temperatures. The most stable appear to be the C60/tetracene and C60/pentacene adducts which decompose at about 608 K.