Pakistan is a bilingual country with nine major and 68 minor languages. It is quite common for English language teachers to use their first language (L1) in their second language (L2) classrooms which is called code switching. This predominant practice of code switching can serve as a filler to ensure the continuity of an interaction or fill a communication gap. Hence, this paper aims to describe the different kinds and purposes of Urdu fillers that three English as a second language (ESL) teachers from Pakistan use when teaching students in ESL courses at the university level. The data consists of four classroom recordings of each teacher’s lectures which have been transcribed for qualitative analysis. The overall findings showed that ESL teachers produced more lexicalized filled pauses than non-lexicalized filled ones in Urdu. The lexicalized filled pauses served as an editing tool, a response marker, an opening frame marker, an empathizer, a time-creating device or a positive reaction. On the other hand, the non-lexicalized filled pauses were used as reaction marker, hesitation marker, device for keeping the floor, device while searching for a word or breathing pause. Hence, this study suggests the importance of fillers as a language teaching and learning tool.