The richest marine source is the macroalgae (seaweeds). Seaweeds are known for their high nutritional value, secondary metabolites and other useful elements that are essential for a healthy lifestyle. The marine ecosystem consists of variety of sea animals, sea plants and other under exploited organisms. The marine environment contains many important minerals and contaminants. The marine living creatures do contain contaminants which on regular consumption may leads to various health issues. The contaminants can be lead, mercury, arsenic, cadmium and other heavy metals which harm the entire ecosystem. The aim of the present study was to evaluate the amount of heavy metals present in the selected seaweeds Padina gymnospora and Ulva lactuca. These two seaweeds were handpicked from Gulf of Mannar Coast. The estimation of heavy metals was analyzed using X- Ray Fluorescence (XRF) and resulted that both the selected seaweeds contained heavy metals at Below the Detectable Level (BDL) which was compared with standard Joint Expert Committee of Food and Agriculture and World Health Organization. The result concluded that the selected seaweeds were safe for human consumption