Special features of nanoparticles such as high surface to volume ratio, homogeneous particle size, high stability and ease of production have led to their widespread use in various fields of pharmacy, dentistry, medicine, biology and materials engineering. In fact, the existence of many pathogenic bacteria that have created many risks in various industries, including medical equipment, dentistry, drinking water treatment and sewage treatment, is another reason for using nanoparticles to protect human health. Meanwhile, the green synthesis of nanoparticles by different strains of cyanobacteria has led to the production of environmentally friendly nanoparticles with various unique biological, physical and chemical properties. Cyanobacteria also have a variety of bioactive compounds such as pigments and enzymes that can act as regenerating and stabilizing agents in the process of producing nanoparticles. In addition, with their unique biochemical compositions that include several bioactive compounds with proven pharmacological activities, they also have potential antibacterial, antifungal, anti-algal, anti-cancer and photocatalytic properties. These properties have caused cyanobacteria to be used not only as useful natural resources, but also to be effective in the prevention and treatment of many diseases. Although many researches have been conducted in the field of biological synthesis using various microorganisms, fewer studies have focused on the use of cyanobacteria in the synthesis of nanoparticles. This article comprehensively examines the characteristics and commercial applications of nanoparticles synthesized by cyanobacteria in different fields, as well as the strategies of toxicity of nanoparticles against living cells.