This paper reports the first time-resolved resonance Raman observation of riboflavin semiquinone anion, neutral, and cation radicals in aqueous solution. These species are short-lived in their unbound state. Therefore, their detection by conventional CW laser excitation, used in previous attempts, was not possible. Information on vibrational frequencies, provided by this work, is essential for probing chemical interactions, such as protein and ligand interactions, in the redox intermediate states of flavin molecules using Raman spectroscopy.