Pitaya is a cactaceae originally from Tropical and Subtropical America which belongs to the exotic fruit group, little explored to date by the food and pharmaceutical industries. The objective of the present study was to evaluate the chemical and physical-chemical properties, antioxidant activity and the fatty acid profile of the red pitaya fruit (pulp and peel) [Hylocereus undatus (Haw.) Britton & Rose], grown in Brazil. These analyses have shown that pitaya pulp has high moisture content (86.03%) and low lipid (0.16%) and protein (2.27%) content, which ensures a low fruit calorie value (53.68%). Among the highlighted minerals are potassium (3.090 mg / 100 g), manganese (2.230 mg / 100 g), chromium (1.250 mg / 100 g), sodium (0.140 mg / 100 g), calcium (0.040 mg / 100 g) and, at lower concentrations, phosphorus (0.003 mg / 100 g). On the other hand, the antioxidant activity of pitaya pulp (1266.3 µg mL -1 ) was lower than in the pitaya peel (445.2 µg mL -1 ). In the fatty portion of the fruit, we verified that the predominant fatty acid is linoleic acid (50.869% of total fatty acids in the fruit), followed by oleic acid (21.551%) and palmitic acid (12.632%). The antioxidant potential and the chemical properties of pitaya fruit can contribute to maintaining a healthy diet.