Olive mill wastewater (OMW) is the by-product of olive oil industrial production. It is characterized by a dark brownish color and a strong odor and is considered one of the most polluted agricultural wastes. In this paper we briefly describe an innovative procedure for the depuration of olive mill wastewater. With this procedure it is also possible to recover valuable substances such as phenolic compounds which have important commercial applications: they can be used in the prevention of cardiovascular disease and as antiviral, antioxidant and antitumor agents. The proposed OMW treatment uses two different packed vegetable matrices which remove most of the pollutant substances by absorption. After filtration of OMW on the matrices the pollutant load of the waste is greatly reduced: the organic content (COD) is reduced more than 80% and the phenol compounds are completely removed.