Abstract The removal of phenols from wastewaters at crude oil production fields is one of the most important challenges in the Arauca-Field of ECOPETROL S.A. (Saravena, Arauca). Based on the review of available technologies for wastewaters treatment with variable phenol concentrations above maximum allowable limits, both at National and International levels, a combined alternative using biological (biodegradation) and physical (aeration - photo oxidation) technologies was considered. The implementation of this combination of technologies allowed the crude oil production field to comply with phenol concentrations at the discharge, obtaining higher than 99% removal efficiency and being consistently lower than the maximum allowable limit set by environmental authorities.