To compare instrumentation time between Hand K-files and Rotary Pedoflex files in primary mandibular molars. Method: A randomized clinical trial was carried on 40 patient aged between of 4–8 years requiring pulpectomy in primary mandibular molars. Patients were equal distributed for instrumentation with Hand K files and Rotary Pedoflex files. During the canal preparation, the instrumentation time was recorded using a stopwatch by an assistant. Results: The mean instrumentation time for Rotary Pedoflex file was 8.41 ± 0.54 min. The mean instrumentation time observed for Hand K-file was 12.05 ± 0.82. Conclusion: The instrumentation time with Rotary Pedoflex files was significantly less as compared to Hand K-file instrumentation.