In order to determine the contaminating influence of heavy metals from anthropogenic sources on the marine biota of the coast of La Guajira, the content of lead, cadmium, nickel, zinc, and mercury in sediment was analyzed by atomic absorption spectrophotometry and liver and kidney of fish of the species Lutjanus (synagris and vivanus) in order to detect possible impacts on the ecosystem. Mean metal concentrations ranged in the sediment as follows: Pb (54.61 to 123.94 mu g/kg), Cd (0.98 -2.84 mu g/kg), Ni (80 to 1220 mu g/kg), Zn (250-630 mu g/kg) and Hg (0.15 to 0.27 mu g/kg). The presence of heavy metals was detected in the tissues of organisms in concentrations of Pb (65 mu g/kg), Cd (5.1 mu g/kg), Ni (2500 mu g/kg), Zn (2450 mu g/kg) and Hg (49 mu g/kg). Taking into account the National Oceanic and Atmospherc Administration of the United States, the species Lutjanus synagris and Lutjanus vivanus present concentrations of Ni, Pb and Zn, within the limits of tolerance to metallic bioavailability, indicating that these metals present no risk for the organisms studied in the marine ecosystem. Concentrations of Pb, Cd and Hg elements determined in liver and kidney of organisms were found below the maximum limits established by the Colombian Institute of Technical Standards for whole fish, medallions and pieces of fish and the maximum content in foodstuffs corresponding to EC Regulation No 466 of the European Commission. The BAF calculated in this study (> 1 in all cases, except Pb) suggests that a significant transfer of metals in sediments to higher trophic levels occurs, especially in the case of Hg.