Impact of Grapevine viroids naturally infectig (Vitis vinifera) cv. Balady: banaty trees on yeild quality was studied. Data on yeild suggest a difference in vine performance espicially in the fruit quality parameters. these differences point to a potential for viroids to affect and reduce growth. whereas changing in vegetative growth, bunches and berries parameters were detected. Grapevine shoot length, Leaf area, leaf fresh, dry weight and leaf dry matter content were reduced in viroids-infected plants than healthy plants. Leaf pigments (chlorophyll a, chlorophyll b, carotenoids) were decreased in viroids-infected plants than healthy ones. Bunch weight, number of berries⁄ bunch, bunch length and width were reduced were reduced in viroids-infected plants than healthy plants. And also berries weight and size were reduced in viroids-infected plants than healthy plants. The total soluble solids (TSS), total soluble sugar,total insoluble sugar content, the total carbohydrate content, the sugar:acid ratio and the alcohol content were decreased in fruit juice of infected plants than healthy ones, while the titratable acidity of fruit juice increased in viroids-infected plants than healthy ones.