It was evaluated the heavy metal content (Cu, Ni, Zn, Cd, Pb) in biota and sediment of an artificial beach (Paraiso) and a natural beach (El Lenguado), both located in San Jorge bay, northern Chile. The results were used to compare both systems, the degree of fulfillment of national and international environmental regulations, and the effect of the construction of the artificial beach on the level of metal contamination historically existing in that area. Equidistant stations were located at each beach in which the organisms were extracted, that ranged from the intertidal to the subtidal. Sediment samples were taken at each beach and slopes were determined with the Emery method. The granulometric analysis evidenced the predominance of medium sand in El Lenguado beach, and medium and fine sand in Paraiso beach. The organic matter content was greater in El Lenguado. In Paraiso beach were determined 5 phylum/superclass, grouped in 19 taxa, while in El Lenguado were found 4 phylum/superclass grouped in 22 taxa. The metal content in sediments and in the majority of organisms shows higher values in Paraiso beach. This results along with the Chilean and American quality norms suggest an evident deterioration of the environmental quality of Paraiso beach, which is demonstrated by an increase in the concentrations of these metals from its construction, which exceed the established limits by both norms.