Aim: To evaluate H-files and K-files in an in vitro study of how fast and effective were the instrumentation in comparison with each other in root canal treatment by taking into consideration time, taperness, and deformities. Materials and Methods: Thirty human single rooted, single canal, and non-carious extracted premolar teeth for orthodontic treatment were collected from private dental clinics and stored in a bottle of thymol. Canal preparations were then divided into two groups: group 1 evaluated K-files and group 2 evaluated H-files. Data were analyzed using SPSS Version 23. Results: Overall, the maximum time taken for root canal preparation was (11.10±1.71 minutes) and the least time taken was (4.43±0.75 minutes). The time taken by both K and H-files for root canal preparation was more in phase I than phase II. In phase I, the time taken by K-file for root canal preparation was more than H-file. However, Mann-Whitney U test showed no statistically significant difference (p>0.05). On the other hand, time taken by K-file was statistically significantly (p<0.05) more than H-file in phase II. Conclusions: This study have shown K-file taking less time than H-file in root canal preparation. Deformities have shown more in H-file and teeth prepared with K-file have shown more tapering. Keywords: Root canal preparation, K-file, H-file