Shellfish is one of the major sources of food for coastal population of Zanzibar. Toxicity of shell fish by heavy metals is of concern to consumers. This study aimed at assessing the metal concentrations of the shellfish along the coast in the neighbourhood of Sea Port of Zanzibar. Shellfish (namely oysters, mussels, clams and crabs) were collected for the assessment on effects of heavy metal contamination among the aquatic organisms. The concentrations of the shellfish were determined using Energy Dispersive X-ray Fluorescence (EDXRF). The concentrations analysed include Cr, Mn, Fe, Ni, Cu, Zn, Cd and As. The range ofCd, Cr, Ni, Mn and Zn were found to be higher in clams while Fe, Pb and Cu were found to be higher in crabs. The values of Cr, Cu, Zn, As and shellfish species appear to be higher than the values reported in the literature.