Grapes have been produced successfully in semiarid regions, but fruit quality may be affected by rootstock selection. In this study, the ‘Isabel Precoce’ grape variety was cultivated onto three different rootstocks (‘IAC 572’, ‘IAC 766’, and ‘IAC 313’), and the physicochemical traits of fruits were evaluated at 14, 19, 21 and 28 days after veraison skin. The results showed that bunches increased significantly in weight and color until 19 days after veraison. In addition, grapes accumulated soluble solids, sugars, and anthocyanins during 28 days of ripening. Moreover, the rootstock used affected bunch length, pulp firmness, and the sugar and anthocyanin contents, but it did not influence skin coloring. In conclusion, ‘Isabel Precoce’ grapes reached maximum weight at 24 days after veraison and maximum soluble solids content, titratable acidity/soluble solids ratio, anthocyanins, and total soluble sugars at 28 days. Fruit on the ‘IAC 313’ and ‘IAC 766’ rootstocks had higher total soluble solids and anthocyanins at 28 days after veraison than ‘IAC 572’. ‘Isabel Precoce grapes’ produced in semiarid conditions showed good quality for fresh marketing and for wine production.