Brazilian beer market presented remarkable increasement last years. Despite of this, Brazilian Amazon states presented discrete growth, with decreasement in some important states as Amazonas. Cubiu (Solanum sessiliflorum) is a fruiting plant which has been used traditionally by people of the upper Amazon and Orinoco basin as artisanal medicine because of its bioactive molecules’ richness. Because of world trend of innovative brewing products as fruit-beers, the aim of this work was to evaluate the composition and antioxidant activity of an artisanal beer added of cubiu. A total of 28 g/L of cubiu’s pulp were added to the beer in maturation’s phase, incubated at 4 °C for 10 days. Compared to a control assay, the resulting beer presented higher turbidity and soluble protein concentration. Total phenolic compounds concentration (435,93 µgGAE/mL) and antioxidant activity (66,36% of free radicals scavenged) were significantly greater than control assay (p <0,001). The results indicates that a low amount of cubiu’s pulp is sufficient to makes the beer functionally antioxidant. The subsequent efforts must to evaluate the acceptance of a beer added of S. sessiliflorum pulp to assessing its market potential.