The low number of students studying or applying for STEM subjects and workforce demand has been prioritized in almost all countries policies. This study intended to examine factors that influenced American and Turkish students to pursue a degree or career in STEM-related fields. Participants of the study were 86 high-ability students selected from two high schools in the United States (n = 39) and Turkey (n = 48). A five-part survey was used and its original version was administered to American participants while its translated version was conducted to Turkish students. Results revealed that "self-motivation" was found to be the most influential factor of STEM interest for American students while "mother" was for Turkish students. In addition, regarding primary reasons for interest in STEM career "self-motivation" was the most important reason for interest in STEM career for American students while "income of occupation" was the one for Turkish students. By stimulating needs for STEM fields, this study will help increase the awareness of the gap between growth in graduates and STEM-related vacancies. Academic institutions will potentially use findings of this study to revise their enrollment policies, with the aim of enhancing enrolment for STEM areas.