Although aggressive behavioural patterns directed by female ungulates to conspecifics of the same sex have been documented for Cervids and Bovids, lethal interactions are very rare. This note reports the observation of a lethal attack carried out by an adult female roe deer to a subadult one. Apparently, the attacking, older female killed the younger one by striking to the throat/neck and abdomen of the latter, with her incisor teeth. Female roe deer are assumed not to defend territories and live in loose, small groups only in the winter months.