Extraction, resolution, and determination of the trans-hydroxycinnamic acids (caffeic, p-coumaric, ferulic, and sinapic) were performed in 82 orange juices derived from the most important blood and blond varieties grown in Italy. Soluble solids, acidity, and anthocyanins were also determined. Hydroxycinnamic acids were more abundant in blood orange than in blond juices. Ferulic acid was the major component in all cases, but the distribution of the four acids was typical in each variety. Discriminant analysis of the experimental results showed that these acids could be used as markers of blood and blond varieties. The statistical model was used to recognize some mixtures of blood and blond juices.