The purpose of this explanatory sequential mixed method study was to identify the level of English as a foreign language (EFL) learners’ intercultural sensitivity (IS) and reveal underlying factors that might have impact on learners’ IS. Participants were 113 EFL learners studying in the preparatory school of a state university. IS scale created by Chen and Starosta (2000) was implemented. Interviews were also conducted with nine volunteer students. Quantitative data were analyzed via SPSS whereas qualitative data were analyzed through MAXQDA program. The descriptive findings indicated that students’ IS level was above the average based on theoretical scoring. Interviews also supported the findings of the scale, and unveiled some underlying reasons for having high scores for each sub-scale. Learners’ suggestions for further development of their IS were also revealed. Therefore, this study might provide some insight for language instructors and administrators who are willing to develop language learners’ IS.