Addition of capping agents like surfactants and polymers during the synthesis of nanoparticles may affect the stability and toxicity of dispersions of nanoparticles. This study revealed the impact of anionic, cationic, and amphoteric surfactants and a cationic polymer on the physical and chemical properties, stability and behavior of silver nanomaterials, as well as on the toxicity of nanosized silver particles with respect to zebrafish embryos. Some of the stabilizers applied were shown to significantly affect embryos of Danio rerio. Colloidal dispersions of stabilized silver nanoparticles were demonstrated to induce a complex mechanism of toxicity with respect to embryos of D. rerio, which is mainly explained by the toxicity of the organic ligand, while other parameters are somewhat inferior. The newly generated data on the toxicity of nanoparticles and their stabilizers with respect to D. rerio embryos reveal the complexity of the toxicity mechanism of nanoparticles impacting living systems.