A short account on the identification in solution of diverse type of vanadium peroxocomplexes is offered. The methodology used is a combination of several techniques, i.e., multinuclear NMR spectroscopy, electrospray ionization mass spectrometry (ESI-MS) and theoretical calculation. The analysis has been carried out in aqueous alcoholic solutions, and in some case also in the presence of appropriate ligands, in order to model some of the natural conditions where vanadium-dependent haloperoxidase enzymes (VHPO) work. With the results obtained, it has been possible to shed light on important aspects of the catalytic cycle of VHPO. Furthermore, a number of synthetic aspects of the reactivity of the various vanadium peroxocomplexes is reviewed.