The standard molar enthalpy of sublimation of Fe(c-C5H5)(2),bis(eta-cyclopentadienyl)iron(II), ferrocene, has been experimentally determined by the Knudsen-effusion method using a quartz-crystal microbalance. The results from two series of experiments were found to be Delta(sub)H(m)(o)(298.15 K) = (74.34 +/- 0.41) kJ . mol(-1) and Delta(sub)H(m)(o)(280.74 K) = (74.60 +/- 0.79) kJ . mol(-1). This property has also been calorimetrically determined at the temperature T = 298.15 K, and the mean value from 12 experiments were found to be Delta(sub)H(m)(o) = (73.19 +/- 0.66) kJ . mol-1. All the literature results for the standard molar enthalpy of sublimation reported to date which have been determined by indirect methods were critically evaluated, and the more reliable values retained. A global analysis including these selected values as well as our effusion and calorimetric results leads to a weighted average value of Delta(sub)H(m)(o) = (73.42 +/- 0.59) kJ . mol(-1) for the standard molar enthalpy of sublimation of Fe(c-C5H5)(2) at T = 298.15 K. From this study we propose the use of ferrocene as a standard reference material for measurements of enthalpy of sublimation.