Matrix-assisted laser-desorption/ionization-time-of-flight-mass-spectrometry (MALDI-TOF-MS) is widely used to identify microorganisms. Recently, new applications such as identification of the animal species from meat, milk or fish are emerging. Standards for the validation of species identifications are still missing. Now, the § 64-LFGB working-group “MALDI-TOF”, established at the Federal Office of Consumer Protection and Food Safety, has compiled a guideline for the validation of species identifications. This guideline is intended for single laboratories as well as for lab networks and shows practical ways for validation of qualitative MALDI-TOF-MS methods. The special opportunities of the technology, in particular the use of extended reference databases and of collections of well-documented individual spectra for validation, have been taken into account in the guideline presented.