Two artificial pilot scale wetlands of 384 l of volume with 60 cm of sand and gravel were evaluated for establish the behavior of Eichhornia crassipes in petroleum production wastewater treatment. One of the wetlands was planted, the other one was used as control. Physical and chemical parameters as pH, temperature, conductivity, dissolved oxygen phosphorus, nitrogen, nitrites, nitrates, COD, BOD, heavy metals, phenol chlorides and oil and fats were evaluated as function of time with residence time of 2 and 4 days at the entrance and exit of the wetland. The planted wetland shows phenol removal of 82%, COD BOD had removals about f 70%, oil and fats 82%, turbidity 86%, showing a high efficiency for this kind of systems. However there were no difference for the removal of heavy metals between the planted and no planted wetland as is characteristic of this kind of systems.