ABSTRACT The fruit of Cactaceas from northeastern Brazil have been the object of many ethnobotanical and functional quality studies. However, a considerable number of species remain poorly exploited, such as the facheiro (Pilosocereus pachycladus Ritter), a native Brazilian plant widely occurring and used in the Caatinga. The objectives of this research were to evaluate the quality, and antioxidant and enzymatic activities of the facheiro fruit during maturation. Fruits were harvested from areas of occurrence of plants in the Paraíba State, Brazil, at three maturity stages, which were determined based on the color of the epicarp (G - green, IP - green with purple traces, and R - completely purple). It was carried out a survey of terms sensorial descriptor terms for fruit appearance and then evaluated the physical, physicochemical, bioactive compounds, antioxidant and peroxidase (POD) activities during maturation. The fruit were described as fleshy berries, with a smooth epicarp; a round, flat shape; opaque purple color; and juicy and soft pulp when ripe. Quality varied during maturation, with the most significant changes being in coloration: the fruit became more purple over time, providing a clear indicator of maturity. With maturation, there was an increase in the content of betalains and total extractable polyphenols, as well as antioxidant activity, by DPPH radical capture method, mainly in the pulp. The pulp of the Pilosocereus pachycladus fruit is an important source of betalains, primarily betacyanins. During maturation, POD activity decreased in the pericarp and increased in the pulp and was strongly correlated with the presence of betalains and with antioxidant activity.