An analysis of the available experimental values of the enthalpy of sublimation of monocyclic, bicyclic, and 'cage' hydrocarbons is performed. Based on the results of this analysis, the value of the enthalpy of sublimation for cubane is found to be anomalous in the series of structurally related hydrocarbons. The potential cause of this anomaly, as well as its impact on the value of the enthalpy of formation of cubane in the gas state at 298.15 K are discussed with emphasis on the reliability of the value, which is used as a key reference value for force field and quantum-chemical computations. (C) 2003 Elsevier B.V. All rights reserved.