Two methods of evaporative cooling system were compared to ascertain the most effective method for the storage of vegetables and okra in New Bussa, Niger State, Nigeria. Two different sizes of earthen pots were installed on a small hole. A small clay pot with bottom surrounded with polythene to prevent leakages was kept inside a bigger clay pot and the inter space was filled with river bed sand which was made moist always by adding water thrice a day In the morning, afternoon, and evening. The pot had a wooden cover. The thermometer and hygrometer were installed to take the record of temperature and relative humidity at interval of time for 14days. The same procedure was repeated in metal in pot but the smaller pot was replaced with 18 liter tin of kerosene. The result obtained showed that there were significant differences p 0.05 in the values of temperature recorded. The highest temperature for both ESC was recorded in the afternoon and the least in the morning this is due to high intensity of the sun in the afternoon and cooling in the morning. Also, the highest relative humidity for both ESC was recorded in the morning due to high cooling effect. It was concluded that pot in pot ESC was more effective compared to metal in pot ESC for storing Okra but none was suitable for storing vegetables in New Bussa region of Niger state, Nigeria and other places of equal climatic data and storage condition. Olaifa, O. Peter | Osaguona, P. O. "Comparative Evaluation of Pot-in-Pot and Metal in Pot Evaporative Cooling Systems" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-3 , April 2019, URL: https://www.ijtsrd.com/papers/ijtsrd23218.pdf