Plants have been always crucial to the life of people. Archaeobotany is a science that, based on the botanical traces preserved at the site (seeds, fruits, vegetative parts, wood, charcoal), allows us to describe many relationships between people and plants. Thanks to archaeobotanical works in Mustis, the first information on the economy of the town and its rural hinterland was collected. The presence of numerous remains of cultivated plants was found, which confirm the significant role of agriculture in the functioning of Mustis. These were mainly cereals (e.g. barley Hordeum vulgare, wheat Triticum spp.) and vegetables (lentil Lens culinaris), but also flax (Linum usitatissimum), a plant with a wide range of applications. The plant based diet was supplemented with fruits such as fig (Ficus carica) and grapes (Vitis vinifera). Surprisingly few finds concern olive seeds (Olea europea), while on the basis of charcoal finds we can assume that olives grew in the vicinity of Mustis. Charcoal research allows us to obtain information on the use of wooden raw material by humans. Based on the remains of firewood, it is also possible to characterize the former forest vegetation. The remains of pine, most likely Aleppo (Pinus halepensis), and pistachio (Pistacia sp.) dominated in the examined samples. Both taxa, together with the olive, indicate the development of Mediterranean vegetation. Among the remaining taxa, remains of fruit trees dominated (almond Amygdalus sp., plum Prunus sp. and apple Maloideae).