ABSTRACT On June 26, 1990, an accidental oil spill occured at a refinery located in Cartagena, Colombia, affecting a 2.5 ha coastal mangrove area and killing all its associated fauna. A special manual cleanup program made it possible to restore part of the polluted soil without harming most of the mangrove plants nor affecting water exchange conditions in the site. Further comparative monitoring programs showed that the ecosystem was totally restored and has grown to a 10 ha forest which is now being used for coastal remediation research.