Analyses of the nutritional composition of tender leaves of three species of Sonchus (S. asper L, S. oleraceus L and S. tenerrimus L) from different locations in the south east of Spain were carried out. The proximate composition, as well as the content of mineral elements (Na, K, Ca, Mg, P, Fe, Cu, Zn and Mn), fatty acids, vitamin C, carotenoids and oxalic acid were determined. The results, which referred to fresh weight, emphasised the low proportion of available carbohydrates. Vitamin C contents were high, and ranged from 457 mg kg -1 (S tenerrimus) to 779 mg kg -1 (S oleraceus). Carotenoids were found in a high proportion (158 mg kg -1 ) in S oleraceus. Mineral element contents were similar to other green leafy vegetables. Fibre was present in amount above 30 g kg -1 in the three species. Essential fatty acids of the ω13 series were highest in S oleraceus (44.97%). It is believed that these species of Sonchus could be used for nutritional purposes, due to the high concentrations of nutrients that they contain.