Passion fruits (Passiflora edulis) have pleasant flavor, an acidic aroma and high vitamins and phytochemicals content. However, they are highly perishable. In this study, the effect of refractance window drying (RWD) temperature and time on nutrients and antioxidant activity of passion fruits was assessed. Response surface methodology (RSM) was used to optimize the drying temperature and time. Moisture, vitamin C, β-carotene and total phenolic content and total anti-oxidant activity were considered as the response variables. Optimal drying temperature and time conditions were found to be 82.5 °C and 60 min, respectively. The respective values for ascorbic acid, moisture, β-carotene, total antioxidant activity, and total phenolic content under optimal drying conditions were 58.8 mg/100 g solids, 11.1% wet basis, 8.8 μg retinol activity equivalent (RAE)/100g solids, 367.6 mg/100 g solids vitamin C equivalent (VCE) and 352.2 mg/100 g solids gallic acid equivalent (GAE), respectively. All models for prediction of these values were satisfactory and had a non-significant lack of fit (p < 0.05). The retention of ascorbic acid, β-carotene, total antioxidant activity, and total phenolic content at the optimal conditions was 90.2, 75.9, 89.7, 88.3%, respectively. Results show that RWD under optimal conditions gives passion fruit powder high nutritional quality.