The distribution of six compounds with three different polyphenol skeletons have been studied in Rosmarinus officinalis: phenolic diterpenes (carnosic acid, carnosol, and 12-O-methylcarnosic acid), caffeoyl derivatives (rosmarinic acid), and flavones (isoscutellarein 7-O-glucoside and genkwanin), each showing a characteristic behavior and distribution during the vegetative cycle. Only in leaves were all six compounds present, and the highest accumulation rate was related with the young stages of development. Rosmarinic acid showed the highest concentrations of all the polyphenols in all organs. The distribution of this acid in leaves, flowers, and stems suggests that in the first stages of flower growth, levels were due to in situ biosynthesis, and in the last stages, the contribution of transport phenomena was increased. The antioxidant activity of six extracts with different polyphenolic composition was evaluated in aqueous and lipid systems. The results clearly suggest that rosemary extracts are excellent antioxidants in both aqueous and lipid systems.