This study aimed to develop a solar chiller for tomatoes pre-cooling under Aswan Governorate climatic conditions. The solar pre-cooling During the experimental portion, the following system was utilized three main separated parts: 1- solar system (source energy), 2- chiller, and 3- pre-cooling cycle. Experiments were conducted in the Faculty of Agriculture and Natural Resources, Department of Agricultural Engineering, Aswan University, Egypt . Latitude 23.30 and longitude 32.90, with an hourly solar intensity of 7 kW.h /m2 maximum solar output in Egypt per day or for a solar declination angle of 450. use of this method for cooling 50 kg of tomatoes crop from 30.66 °C to 15.4 °C under the experiment's circumstances, It is clear that as the temperature of tomatoes fruits decreases the cooling time increases and decreases the cooling water temperature. An exponential relationship is the justified, minimum and maximum temperature of tomatoes fruits were at 15.4oC and 20oC at a cooling water temperature of 5oC and 15oC respectively. The experiment indicated that reducing the temperature of the cooling water tends to increase on refrigeration load. it was clear that cooling water temperature is decreased from 15 to 5°C increases refrigeration load from 0.367, 0.460 to 0.602 ton at a water flow rate of 6 l/min. reached its maximum value at 0.6258, 0.5677, and 0.55 % of refrigeration at cooling water temperatures 5, 10, and 15oC respectively it was clear that, decreasing the temperature of the cooling water as the performance coefficient increased.