This study was conducted to develop a low cost method to preserve papaya (Carica papaya L.) pulp at ambient temperature with a combination of treatments including acid, heat, and cinnamon oil. Papaya pulp processed without and with 200 ppm cinnamon essential oil at pH 5.1, 81 °C, 7 min (ST2 and ST3); pH 3.9, 69 °C, 13 min (ST4 and ST5); and pH 4.5, 75 °C, 15 min (ST6 and ST7) was stored for 8 weeks at ambient temperature (28±2 ºC). The cinnamaldehyde content of the papaya pulp treated with cinnamon oil decreased significantly during storage. ST5 and ST7 retained significantly higher β-carotene contents and lightness values compared to ST4 and ST6 during storage. The results indicated that acidification of papaya pulp to pH 4.5 and pasteurization at 75 °C for 15 min with 200 ppm cinnamon oil can be applied to obtain safe and high quality product, which is stable for 8 weeks at ambient temperature.