The extracts of seven Citrus rootstock seeds have been compared regarding fatty acid profile and antioxidant potential. Sour orange (Citrus aurantium L.) was found to contain the highest oil amount (34%), while the Poncirus trifoliata cultivars contained the highest percentage of unsaturated fatty acids (84-87%). In addition, the antioxidant properties of the extracts from defatted seeds have been evaluated by measuring their radical scavenging activity against 2,2'-diphenyl-1-picrylhydrazyl. The highest antioxidant activities were observed in the case of the acetone extract of sour orange and Citrumelo Swingle (76% and 75%, respectively), at a concentration of 0.17 mg mL(-1). Moreover, the total phenolic content of the extracts, determined using the Folin-Ciocalteau reagent, was found to be correlated with the radical scavenging activity results. The acetone extracts of sour orange and Citrumelo Swingle exhibited the highest phenolic content [112.3 and 103.4 mg gallic acid equivalent g(-1) dry sample weight, respectively].