Conjugation effects on the thermodynamics of ground-state and lowest-singlet excited-state double hydrogen-atom transfer reactions in 7-azaindole and related models are studied with ab initio electronic structure methods. The results indicate that the extended conjugation of the system has a large effect on the relative energies required for hydrogen-atom transfer. The observed energy differences are mainly attributed to stabilization of the tautomer species by enhancing low-energy resonance structures and by allowing for efficient delocalization of excess charge in the reaction center.