The invention of LASER and using it as a tool in dental therapy had made a revolution in this field, especially in periodontics, which drew a lot of attention to modify this technology in such a way to overcome the drawbacks of traditional periodontal therapy. From this point, this study was conducted to clinically compare the efficiency of using Er:YAG LASER in the treatment of chronic periodontitis, which is a common periodontal disease, with that of ultrasonic and hand instruments. The results supported the superiority of LASER therapy regarding the improvement in clinical parameters. In addition, patients treated by this approach experienced the minimal levels of pain during therapy when compared to that of traditional periodontal therapy. Accordingly LASER could be considered as an efficient and comfortable alternative for periodontal scaling and root planing by ultrasonic devices or hand instruments.