Red fleshed pitahaya fruit (Hylocereus polyrhizus) is highly perishable, thus commercialization is rather limited. A study was conducted to determine the effects of maturity, natural antifungal treatment and packaging on postharvest quality of pitaya fruits. For maturity study, fruits were harvested at three stages based on color indices (Stage 1: green color with area between the bracts turned light red; Stage 2: 50% of skin turned light red; Stage 3: entire skin turned light red) and were then stored for up to four weeks at 5 ºC. Fruits harvested at full color stage were most superior in terms of appearance, flavour and nutritional quality after four weeks of storage at 5 ºC. However, storage life of such fruits was reduced to three weeks only, due to disease development. While, fruits harvested at earlier maturity stages which could be stored longer, were not able to attain the appealing skin color and eating quality as the full color stage fruits. The essential oils are reported to have some fungicidal properties against certain postharvest diseases of tropical fruits and vegetables; and unlike synthetic, they are safe for the environment. The effects of pre-storage treatment of Cymbopogon nardus oil at different concentrations (0.5, 1, 2, 3, 4, 5 %) on quality of pitahaya fruits stored at 10 °C were determined. The untreated fruits served as control. Results showed that Cymbopogon nardus oil treatment at concentrations from 0.5% to 1% was effective in delaying disease incidence and extending storage life of pitaya for up to two weeks at 10ºC without compromising its quality attributes. On the other hand, higher concentration (more than 2%) of Cymbopogon nardus oil has resulted in some phytotoxic effects on fruits. For washing treatment study, fruits were treated with C: control (Unwashed fruits); T1: Tap water; T2: 125 ppm chlorine and T3: 1.5 ppm ozonated water. After drip drying, the fruits were individually packed with 0.04 mm LDPE plastic bag and stored for 7 days at ambient temperature (25±1 °C; RH 65-70%). Results indicated that washing treatment did not significantly affect most of the quality attributes tested. Nevertheless, washing treatment using ozonated water offers a promising method in improving fruits appearance as no water soak formation developed on the flesh. Washing with 1.5 ppm ozonated (T3) water also has a potential to reduce ethylene production. Taken togetherpitaya fruits best harvested once the entire fruit skin turned light red; Cymbopogon nardus oil at concentration as low as 0.5% is a promising natural anti-fungal treatment for pitaya; ozonated water at concentration 1.5 ppm ozonated is a promising washing treatment to extend its storage life.