The discovery of several 5000-year old seeds of wild watermelon, Citrullus lanatus, at an archaeological site Uan Muhuggiag in southwest Libya, re-opens the debate on the origin, wild distribution and domestication history of this species. The seeds were found within a plant assemblage of wild seeds and fruits, associated with pottery and bones of domestic animals belonging to Neolithic pastoralists. The presumed wild progenitor of the modern cultivar C. lanatus is today found exclusively in a region centring on the Kalahari Desert. This new archaeobotanical record raises the possibility that this distribution was much more extensive in the past. Keywords: Citrullus lanatus, Libya, Wild distribution, Domestication history.