This paper investigates how customer involvement influence purchase intention and purchase behavior from King Power duty-free shops in Thailand. Based on planning behavior theory, we examine the structural relationships customer involvement, purchase intention and purchase behavior. The results indicate that advertisement involvement, product involvement and affective involvement have positive influence on customer purchase intention. Advertisement involvement and product involvement have positively impact on purchase behavior, but affective involvement has no significant impact on customer purchase behavior. Our results also show that customer purchase intention is significantly positive relation to purchase behavior. More results and implications are discussed toward the end.