The purpose of this work is to (re)interprete some spectral and thermochemical properties of 1H-phospholes. The first topic covers the assignment of absorption bands in their photoelectron and UV-vis electronic spectra. Our goal is to unravel the electronic origin of the observed bands. The second topic deals with their basicity. We investigated the site of protonation and the basicity of 1H-phospholes in both the gas phase and acidic solution. To elucidate structure-property relationships, we studied in a systematic way the influence of common substituents on the electronic structure and emphasized the corresponding consequences for the spectral and thermochemical properties. The geometric and electronic structures were investigated using adequate quantum-chemical techniques including multiconfiguration SCF and density functional theory based methods.