This chapter presents data pertaining to the biological accumulation of metals in the biomass of specific cyanobacteria. The results are divided between a discussion of the optimal conditions for the maximum accumulation of metals by the cyanobacteria cells, and analysis of the mechanisms of biological absorption and accumulation. Besides metal biosorption, this chapter also draws attention to the possibility of obtaining biomass enriched with organically bound metals. Certain metals are vital for human functioning, and their deficiency can affect various vital functions. Metals can build coordination compounds with organic molecules, including enzymes and metalloproteins. Metallic-organic compound substances are very prospective because of their low toxicity and high biological efficiency. A promising and recent direction of biotechnology is the obtainment of such compounds, which may have various possible food and therapeutic uses. In this chapter the results of different metal accumulation (iron, zinc, selenium, chromium, copper) in the spirulina biomass are presented. Furthermore, the distribution of accumulated metals in different fractions of biomass (amino acids and oligopeptides, proteins, lipids, carbohydrates) is shown.