The increase of industrial activities has accentuated environmental pollution problems, due to the accumulation of harmful pollutants, such as heavy metals. In regard to its simplicity, biosorption on nonconventional and low-cost materials has gained credibility in the last few years, because it offers an efficient and cost-effective alternative to the conventional decontamination techniques. From this perspective, numerous applications of marine algae biomass have been developed for the efficient removal of heavy metal ions from aqueous environments . In this chapter, the biosorptive characteristics of marine algae biomass (marine algae and marine algae wastes) for different heavy metal ions from aqueous solution are described, as a function of experimental conditions (solution pH, biosorbent dose, contact time, temperature, etc.) and the experimental procedure used in the biosorption process. Application of isotherm and kinetic models used for the mathematical description of experimental data is also reviewed. The biosorption mechanism has been found quite complex, including adsorption, surface precipitation, ion exchange and complexation.