Vineyards of ‘Niagara Rosada’ have shown great productive potential. However, the grape production has been affected by factors related to climate adversities. Thus, this study aimed to evaluate the effect of plastic cover and bagging of bunches of ‘Niagara Rosada’, in Almirante Tamandaré, PR, Brazil. Plastic cover used was of polyethylene with 250 µm of thickness and bagging of the bunches with white non-woven fabric bags. The treatments were: without plastic cover over the vineyard and without bagging of bunches (control); with plastic cover over the vineyard and without bagging of bunches; with plastic cover over the vineyard and with bagging of bunches; and without plastic cover over the vineyard and with bagging of bunches. To determine the quality of the grapes, we evaluated weight of the bunches and berry, width and length of the bunch, number of berries per bunch, total soluble solids (SS), titratable acidity (TA), pH, and SS/TA ratio. In both crop seasons, treatments with the protected plants or bunches were superior in all evaluated traits. The plastic cover and bagging of bunches delayed maturation and improved the physical and chemical characteristics of bunches and berries of ‘Niagara Rosada’.