Reclamation of olive-oil mill wastewater (OMW) from two-phase extraction procedure was carried out in a continuous stirred tank reactor (CSTR) at a pilot plant scale by Fenton-like process. The effect of operating conditions such as pH, space–time, H 2 O 2 and Fe(III) doses, as well as [FeCl 3 ]/H 2 O 2 ] ratio on the efficacy of Fenton’s process was investigated. It is demonstrated that Fenton’s process can effectively degrade organic matter in OMW. In the start-up stage, Fenton reaction reached steady state within 3h. Oxidation of organic materials in OMW was pH dependent and the optimal pH was found to be 3. The optimum [FeCl 3 ]/[H 2 O 2 ] ratio was in the range 0.026–0.058w/w, with Fe(III) concentration between 0.35 and 0.40gdm −3 . The final values of COD and total phenols at the outlet of the pilot plant were close to 129mgO 2 L −1 ([COD] initial =4017mgO 2 dm −3 ), and 0.5mgdm −3 ([total phenols] initial =66.2mgdm −3 ), respectively. Finally, the produced water can be used for irrigation or discharged directly into the municipal wastewater system for ulterior tertiary treatment.