I.D. SărdărescuMore than 80 viruses are reported as causing damage to the grapevine, but some of them are rare and cause negligible damages. However, other viruses are veritable pathogens for this crop, affecting the production quantity and quality, such as: grapevine leafroll-associated virus serotype 1+3 (GLRaV-1+3), grapevine fleck virus (GFkV), and grapevine fanleaf virus (GFLV). In this study, we present the effects of Serlac V, Growspore Vita and Nutryaction biostimulants on the grapevine plants belonging to 'Valerien' and 'Italia 93 Mf.' genotypes infected with GFkV and 'Cardinal 74 Mf.' genotype infected with GLRaV-1+3 and GFkV. Determinations have been made regarding the content of assimilating pigments in leaves (chlorophyll a, chlorophyll b, and carotenoids), a diameter of the cane and of the pith, leaf surface, stomata length and ostioles opening.