The objectives of this research were to determine the changes in quality and oxidative stability of tomato seed oil, including color, antioxidant activity, peroxide value, saponification value, iodine value and acid value, during heating for 50 h at a common frying temperature (180 C) and under different storage conditions of temperature (25 C and 35 C), light, and headspace volume (10 mL and 25 mL in 50 mL container) as a function of storage time (up to 210 days at 25 C and 105 days at 35 C). Results showed that tomato seed oil had high thermal stability with excellent physicochemical profile after heating. The antioxidants such as tocopherol and polyphenol were likely the most significant contributor to the high thermal stability. High temperature, exposure to light, and large headspace volume significantly accel- erated the deterioration of tomato seed oil during storage, among which the temperature had the most pronounced effect followed by light and headspace volume. It is suggested that tomato seed oil is packaged with minimal light exposure and stored at a low temperature. The study provided important information for the quality evaluation and control of tomato seed oil and has a great significance for value-added utilization of the by-product from tomato processing industry.