Several strains of microalgae Sprirulina platensis, Nostoc linckia and Porphyridium cruentum were studied to assess their ability of silver nanoparticles formation. In the experiments the synthesis of nanoparticles in silver nitrate solution was carried out as during the initial cell cultivation as well as in harvested (dead) microbial biomass suspended in silver nitrate solution. The time dependences of silver nanoparticles production process for each strain were established. A variety of spectral and analytical methods was used to characterize the obtained silver nanoparticles: UV-vis spectrometry, scanning electron microscopy (SEM) with energy-dispersive analysis of X-rays (EDAX), neutron activation analysis (NAA), and atomic absorption spectrometry (AAS). It was shown that the produced bacterial biomass with silver nanoparticles can be used for industrial as well as medical and pharmaceutical purposes.