Catalytic wet oxidation of simulated olive oil wastewaters has been investigated in batch and trickle-bed reactors. The comparison between two operating reactor systems is presented querying the effect of temperature and pressure. The higher decontamination rates of organic matter were obtained in the batch reactor, which has promoted the complete mineralization of liquid pollutants after 60 min at 200 degrees C and 30 bar. At equivalent operation times, the batch reactor exhibited higher decontamination efficiencies when compared to the continuous flow trickle-bed reactor. Additionally, the effect of pressure on TOC removal became less significant when compared to the influence of oxidation temperature for both reactor configurations.