To evaluate the water quality along the continental shoresof Venezuela, where fishing communities exploit the clam Tivelamactroides, the concentration of heavy metals (Cu, Mn, Fe, Zn,Cd, Ni, Pb y Cr) was determined in superficial sediments,together with environmental factors (temperature, salinity,dissolved O2, pH, phytoplanctonic biomass, seston, and total Nand P) of the litoral waters of Playa Güiria on the northeasterncoast (Sucre State), and of Río Chico and Boca de Paparo (MirandaState), two localities on the central coast separated bysome 5km and influenced by the Tuy River. In Río Chico, andmainly in Boca de Paparo, the concentration of heavy metals inthe sediments (>18μg·g-1 Cu, >3μg·g-1 Cd, >5μg·g-1 Cr, >0.9μg·g-1Pb, >11μg·g-1 Ni) and the environmental factors (>28ºC,<5.6ml·l-1 dissolved O2, >55μmol·l-1 total N, >17μmol·l-1 total P)indicated the presence of polluted systems. This environmentaldamage was linked to the influence of the Tuy River, which flowsinto the sea at Boca de Paparo. The values for heavy metalswere higher than the values reported 14 year ago. In PlayaGüiria the values determinated did not show environmentalcontamination (0.03μg·g-1 Cu; 0.5μg·g Cd and no Cr, Pb or Niwere detected). Shore cleanup at Boca de Paparo and Río Chicois recommended, as these locations have dangerous sanitary andenvironmental conditions. Environmental conditions at PlayaGüiria allow for Tivela mactroides fishing.