CCSD(T) theory has been applied to the ethyl radical using aug-cc-pVDZ, cc-pVTZ, and cc-pVQZ basis sets, and extrapolated to the complete basis set limit, QCISD/6-311G(d,p) results were used to estimate unknown frequencies in C2H5, and zero-point energies were combined with a correction for core electron correlation to find a 0 K bond dissociation enthalpy of 416.0 kJ mol(-1) (422.5 kJ mol(-1) at 298 K). This corresponds to Delta(f)H(C2H5) values of 131.5 and 120.5 kJ mol(-1) at 0 and 298 K, respectively. Uncertainties of +/-2.1 kJ mol(-1) are assumed.