To evaluate toxicity of silver nanoparticles synthesized by using the reverse micelle formation method, the effects of nanoparticles on lipid peroxidation and morphological changes of cell membranes in human lymphocytes were studied. It was found that under the influence of nanoparticles a reduction in cell viability and formation of excessive levels of reactive oxygen species were observed. Silver nanoparticles at different concentrations activate the processes of lipid peroxidation and, as a consequence, led to morphological changes in human lymphocytes.