This study was conducted to determine the effects of high temperature and deficit irrigation on growth and yield of hot pepper. Hot pepper was subjected to four irrigation treatments: fully irrigation (FI), 10, 20, and 30 days deficit irrigation (DI) combination with high temperature treatment. Control plants were grown natural environment and conventional culture methods. The plant height treated with high temperature was significantly higher than that of control plant. At FI combination with high temperature treatment, growth parameters such as stem diameter, leaf area, fresh and dry weight were the greatest. The yield was the greatest (2,036 kg/10a) under control, DI combination with high temperature treatment decreased by approximately 42% compare with FI combination with high temperature treatment. The number of abnormal fruits was approximately 38/plant under control, which was the smallest and that of 30 days DI combination with high temperature was higher 3.3 times compare with control. Flower abscission and calcium deficiency induced by DI treatments, especially those physiological disorder promoted by increasing DI treatments period. Results indicated that yield of hot pepper reduced by DI treatments, these results suggest that the growers should irrigate to proper soil moisture for preventing reduction of total fruit yield.