The paper presents the results of four-ear trials of preparations with silver nanoparticles Ze-rox, Zeromiks, and Zerebra Agro on varieties with varying degrees of resistance to the main potato diseases. The four-ear trials made it possible to conclude that preparations with silver nanoparticles were effective in protecting potatoes from rhizoctoniosis and alternariosis, comparable to the effectiveness of chemical treaters (Maxim and Celeste Top) and fungicides used in the treatment of vegetative plants (Abiga Peak andRidomil GoldMC). The biological effectiveness of preparations with silver nanoparticles was lower than that of Abig Peak by an average of 49.8% against late blight on the unstable Ilyinsky variety. The biological effectiveness of Zerebra Agro was low (24.6%) in relation to late blight on the Sante variety in the epiphytotic year. It was high (65.7%) in the non-epiphytotic year, and it was not much worse than chemical fungicides (30.4 and 78.1%, respectively) in both the epiphytotic and non-epiphytotic years. In 2018, when the effectiveness of the preparations was high for all major potato diseases, the yield increase was significantly higher than the check. In the standard version, it exceeded the check by 26.4%, in the variant with Zerebra Agro - by 27.1%. No significant difference was found between the standard variant and Zerebra Agro.