Background: Fear from dental injection among children is considered the main obstacle to the dentist while delivering local anesthesia. So, this study used a pre-cooling technique at injection site and compared it to conventional methods. The study aimed to assess external cooling efficiency on the injections’ pain of at the site of local anesthesia in children had dental treatment. Materials and Methods: The study subjects were 60 children with dental treatment in mandibular region. The study group were anesthetized after cold application of the injection site for 2 minutes, while the control group were administered local mandibular anesthesia after topical anesthesia application. Independent student t-test was used for means comparison. Results: The pain scores were lower in the study group with no significant difference between groups (P <0.5). Conclusions: There was no significant difference between the study and control groups on the injection pain, but it was more tolerable by children and easier to apply than conventional topical anesthesia.