The employment of the mother tongue or first language (L1) in foreign (FL) or second language (L2) teaching is a controversial issue and still continues to take considerable attention from researchers. Hence, the current study attempted to shed light into the use of L1 in Turkish EFL classes. In particular, it focused on the amount and the functions of L1 used by primary school EFL teachers in Turkish context. Moreover, it also aimed to investigate EFL teachers' perceptions towards the use of L1 and compare it with their actual classroom practices. Three EFL teachers participated in the study. The data of the study were collected through observations and semi-structured interviews. The data of the study were analyzed both qualitatively and quantitatively. The findings revealed that the three Turkish EFL teachers used comparable amount of L1 in their classes, ranging from 21% to 30% of all classroom instruction. The current study seemed to indicate that Turkish EFL teachers were inclined to use more L1 in lower grades. The findings also revealed that EFL teachers used Turkish in 9 different functions such as giving instruction, translation of unknown words, classroom management, checking understanding, eliciting, drawing attention, giving feedback, grammar instruction, and translation of sentences, respectively. The results also demonstrated that the perceptions of EFL teachers towards the use of L1 comply with their actual practices with minor differences.