Abstarct: Using first language now seen as a common phenomenon and strategy of EFL teachers, has been discussed from different viewpoints in terms of its helpfulness or deterrence for the past decades. Building on the previous research, this study aimed at pursuing three main goals. First and foremost, this study aimed at discovering the situations in which teachers employ first language in an EFL classes. The second goal was to identify the role of learners' language proficiency on teachers’ decision to employ first language. Finally, the third goal of the study was to see if the teachers’ experience had a role in determining teachers’ decisions in using first language in their EFL classes. The researcher collected data from 70 males and female EFL teachers with varying ages, degrees and experience via online interviews. Using thematic analysis, the data were analyzed qualitatively in several phases, i.e., familiarity with the data, generating initial codes, searching for themes, reviewing potential themes, defining and naming themes, producing the report. baxsed on the data obtained, the results showed that most of the teachers use first language in classes where learners are in lower language proficiency level. In addition, it was demonstrated that more experienced teachers are less inclined to use first language as a teaching technique. The difference is dramatically huge when the teachers with one to five years of experience are compared with those with over 15 years of implications.