The 364-nm photoelectron spectrum of pyrrolide anion, prepared by deprotonation of pyrrole, has been measured. The electron affinity (EA) of pyrrolyl radical has been determined to be 2.145 +/- 0.010 eV. Harmonic vibrational frequencies of 925 +/- 65, 1012 +/- 25, and 1464 +/- 20 cm(-1) are observed in the spectrum of the (2)A(2) ground state of pyrrolyl. This spectrum is well reproduced by Franck-Condon fitting on the basis of the optimized geometries and the vibrational frequencies of the anion and the radical obtained at the B3LYP/6-311++G(d,p) level of density functional theory (DFT). The observed vibrational modes involve large displacements along the ring coordinates. While the Franck-Condon analysis also predicts a very similar spectrum for the B-2(1) first excited state, only a broad, featureless, weak spectrum is observed near the calculated binding energy. The DFT calculations find a transition state for B-2(1) electronic symmetry as a result of strong vibronic coupling between the (2)A(2) and B-2(1) states. The transition state is located very close to a conical intersection of these states. The absence of distinctive features for the 2 B, transition state in the spectrum arises from the associated lifetime broadening. Using the EA of pyrrolyl together with the N-H bond dissociation energy (BDE) of pyrrole recently determined by Ashfold, the gas-phase acidity of pyrrole is Delta(acid)G(298)(RH) = 351.9 +/- 0.4 kcal mol(-1) and Delta(acid)H(298)(RH) = 359.4 +/- 0.4 kcal mol(-1). The gas-phase acidity of pyrrole was also independently determined relative to methanethiol using a tandem flowing afterglow-selected ion flow tube. These measurements now provide a much more accurate set of benchmark acidities for pyrrole and methanethiol, a frequently employed reference acid.