This study aims to explore the inquiry-based teaching strategies employed by mathematics teachers in lower secondary classrooms. The inquiry-based teaching strategy provides an opportunity for learners to learn mathematical concepts by 'exploring', 'conjecturing', 'reasoning', and 'evaluating' (Arendas, 1994; Jaworski,1994; Borasi, 1992). The study was conducted in a government and a private school in Karachi, Pakistan. The research participants were mathematics teachers from lower secondary classes (class 8) who had at least two years' teaching experience in mathematics. A qualitative case study approach was employed to get an in-depth understanding about the mathematics' teachers teaching practices. Furthermore, an inductive analysis was used to investigate teachers' understanding and classroom implementation of the inquiry approach. The study provided an opportunity to examine both the teachers' teaching strategies and its effects on students' learning. The findings of the study reveal that both the teachers employed low level of inquiry (cookbook) approach and seemed constrained to use a high level of inquiry (independent) due to time constraints and the need to complete the syllabus on time. Moreover, less content and pedagogical knowledge also created hindrances in teaching students through an inquiry-based approach. The study suggests that teachers need to be provided with continuous help and assessment following their participation in professional training programmes. The study will contribute towards teacher training institutions and teacher educators when they design or conduct trainings for mathematics teachers. The training institutions might consider the needs of mathematics teachers and the challenges that teachers face in teaching mathematics.