Abstract We have measured the jump in the specific heat at the superconducting critical temperature of lead. We find ( ΔC) T c = 57.5 ± 0.6 mJ- mole −1-° K −1, which is substantially higher than the previous calorimetric determination by Clement and Quinnell but which is in good agreement with the value obtained by Decker et al. from the temperature dependence of the critical field. Our result is relevant to the question of the energy dependence of the energy gap parameter Δ( ϵ, T) in the BCS theory of superconductivity. We conclude that Δ( ϵ, T) rises with ϵ, for small ϵ, in qualitative agreement with the calculations of Culler et al.