The characteristics and composition of hackberries (Celtis australis L.) from Mediterranean forests were stablished and compared to other fruits. Fresh hackberries were fractionated in peel (19.8%), flesh (49.7%) and stone (29.4%). A very high value of soluble solids (53.6 ºBrix) was found in the flesh. Chromatographic analysis indicated that the flesh soluble solids were mainly sucrose (12.8%), glucose (17.5%) and fructose (21.8%). An average antioxidant activity (FRAP) of 4000 μmol eq. Fe2+/100 g and a DPPH scavenging capacity (IC50) of 7 were found. The antioxidant properties are due to the content of phenolic compounds and flavonoids, 249 and 28 mg/100 g, respectively, in the flesh. The dietary fibre in the flesh was 18 g/100 g. The hackberries flesh cell wall is constituted by pectins (55.7%) and hemicelluloses (44.4%). According to these results, hackberry would be considered of great interest for its applications as sweeting agent with antioxidant, thickener and dietary properties, in the food industry.