Laser ablation gnerated AuC3H- anions were skimmed into a time-offlight mass spectrometer (TOF-MS) and selected with a mass gate. Photoelectron spectra of AuC3H- were recorded using the velocity map imaging tethnique at several photon energies. The experimental spectra, quantum chemistry calculations, and Franck-Condon simulations suggest that the AuC3H- cluster has four structure isomers, including one unexpected structure of [C=C=C-Au-H](-). When AuC3H- is compared with C3H2-, introduction of gold into the hydrocarbon system results in the much lower isomerization barriers.