AIM: To evaluate and compare the pain perception, anxiety level, and acceptance of Er,Cr:YSGG laser (2780 nm) with a conventional rotary method during cavity preparation in children. MATERIALS AND METHODS: In a randomized controlled trial, using split-mouth design thirty 6- to 12-year-old children with 60 carious molars were examined. In one quadrant, cavity was prepared conventionally by airotor while, in the other quadrant, Er,Cr:YSGG laser was used. Anxiety was assessed by measuring pulse rate using a fingertip pulse oximeter, while the pain was measured on the Wong-Baker Faces Pain Rating Scale. After the cavity preparation by both the methods, the child was asked about the preference for future treatment of a carious lesion. RESULTS: Pulse rate was found significantly higher in the airotor group but no significant difference in pulse rate was found in the laser group when compared to the baseline pulse rate. The mean value of pain in the airotor group was slightly higher than the laser group. Fifty-seven percent of children preferred Er,Cr:YSGG laser for cavity preparation in the future. CONCLUSION: During cavity preparation, Er,Cr:YSGG laser comes out to be more effective and acceptable, as it is less anxiety-provoking and may cause less pain when compared with the airotor. CLINICAL SIGNIFICANCE: Er,Cr:YSGG laser helps the children to remain calm during the cavity preparation. HOW TO CITE THIS ARTICLE: Alia S, Khan SA, Navit S, Comparison of Pain and Anxiety Level Induced by Laser vs Rotary Cavity Preparation: An Study. Int J Clin Pediatr Dent 2020;13(6):590-594.