The present study compared the short-term effects of a diesel oil spill on the strucure and function of nematode and macrobenthic assemblages between tidal flats with different history of exposure to oil perturbation. A manipulative field experiment was conducted, where oil exposed treatments were contrasted with controls, during four successive times, two before and two after the oil spills. During the oil spill the death and the presence of diverse debilitated macrofaunal organisms were observed in the oil treatments. However, 24 h later no significant changes were identified, suggesting that the impacted plots were quickly recolonized. Nematode assemblages showed a decrease in overall density and an increase of r-strategist traits such as non-selective deposit feeders and colonizers at perturbed treatments from one of the historically non-perturbed tidal flats. We discuss the mechanisms responsible by distinctive patterns of response observed between the two benthic components.