Passiflora edulis Sims is a perennial plant species native to Brazil that exhibits attractive and aromatic flowers. Parts of P. edulis Sims are reported to be used in folk medicine for the treatment of anxiety, insomnia, epilepsy, spasms, pain, inflammation, alcoholism, among others. The antioxidant activity exhibited by such species is attributed to phenolic contents in tissues. The objective of this study was to determine the extent of reactive oxygen species (ROS) scavenging by ethanolic extracts of P. edulis parts harvested at flowering and fruiting stages of plant development. Leaves, roots and fruit pulp and mesocarp were obtained from plants grown at Pitangueiras Farm (Sooretama-ES) from November 2016 to February 2017. Fruit mesocarp (77.4%) and root extracts (75.0%) obtained from plants at fruiting stage were the most potent scavengers of superoxide anion (O2-), followed by fruit pulp (55.7%) and leaf (43.6%) ones. As for samples collected at flowering stage, root extracts (61.3%) were still more efficient than leaf extracts (41.5%) in scavenging O2-. The total phenolic contents, determined as percentage relative to tissue fresh weight, in fruit pulp, fruit mesocarp, roots and leaves was 0.4 ± 0.2%, 4.5 ± 2.5%, 27.4 ± 13.9% and 71.0 ± 18.8%, respectively, while roots and leaves from plants at flowering stage accumulated 6.9 ±6.8% and 57.1 ± 28.9% phenolics. The results suggest that the diversity of phenolic compounds vary according to P. edulis tissue and plant developmental stage, which can explain, in part, the distinct ability of ethanolic extracts to scavenge O2-.