The co-adsorption of carbon monoxide and benzene on Rh(1 1 1) has been studied using density functional calculations. We used the ordered p(3 x 30) surface unit cell for the study. Besides, a comparison of the co-adsorption with CO and benzene two-dimensional networks is also given. The hydrogen of the benzene ring presents a bonding angle of 26 degrees. The electronic structure reveals that the CO does not interact with benzene. Regarding the bonding, the Rh-Rh overlap population decreases 36.7% after co-adsorption, which is almost, the same decrease after CO adsorption. The CO-benzene interaction is very weak and a small H-benzene-C-CO OP of 0.001 is detected. (C) 2010 Elsevier B.V. All rights reserved.