As oil and gas production moves to more challenging high-temperature conditions using corrosion inhibitors to mitigate carbon steel corrosion in high-temperature environments becomes more difficult for two reasons. One reason is that the chemicals are susceptible to thermal degradation at high temperatures. This degradation can reduce inhibition performance and produce a solid formation to block injection tubing. The other reason is that a satisfying inhibition performance can only be achieved by significantly higher chemical dosages at high temperatures compared to dosages at lower temperature. The effectiveness of corrosion inhibitors typically decrease as temperature increases. To maintain a satisfying performance the dosage rate may be too high to be economical or it might exceed the injection system’s capability.This paper describes recent efforts to address these two concerns for high-temperature corrosion inhibitors. The comparison of chemical inhibitors’ performance before and after thermal aging was used to determine their thermal stability limit. Through a systematic performance evaluation at different inhibitor concentrations accurate estimation on thermal stability limit and thermal degradation kinetics can be obtained by comparing thermally aged and un-aged inhibitor intermediates. Furthermore the effectiveness of corrosion inhibitors at high temperature was investigated and compared among different inhibitor groups such as imidozolines quaternary amines and phosphate ester compounds. Overall the thermal stability and effectiveness of corrosion inhibitor intermediates are combined to determine their suitability for high-temperature applications.