Sargassum natans and Sargassum fluitans are brown algae with the ability to travel long distances through the ocean currents. The repetitive invasive episodes of Sargassum natans and Sargassum fluitans on the Caribbean coasts during the last years have become a first-order problem, threatening tourism and fishing. Therefore, appropriate solutions like taking advantage of algal biomass, are necessary. Furthermore, it is also known the capacity of these phaeophyceae to accumulate heavy metals, many of which exhibit remarkable toxicity and persistence in living organisms. The objective of the present research is evaluating the presence of heavy metals in the Sargassum of the Dominican coasts, using Atomic Absorption Spectroscopy (AAS) technique. Studied metals were cadmium, copper, chromium, nickel, lead and zinc; since these have been proven to be dangerous to health. However, the results indicate the levels of heavy metals in the Sargassum do not represent, a potential danger to health and the environment; opening the possibility to use algal biomass for various applications. In addition, it was evidenced there is not a significant difference between the metal biosorption of both species of Sargassum studied.