The purpose of this study was to compare the effectiveness of a three-in-one injection comfort system (ICS) and 10 percent lidocaine pump spray in reducing injection pain in children. Fifty eight- to 12-year-old children treated at a university pediatric dental clinic participated in this study. The Children's Fear Survey Schedule-Dental Subscale was used to select nonanxious children to participate. Contralateral tooth pairs were treated in two separate visits with random use of either ICS or lidocaine pump spray. The pain perception levels were assessed with heart rate changes, the Modified Behavioral Pain Scale (MBPS), and the Wong-Baker FACES Pain Rating Scale (WBFPRS). At the end of the second visit, children's preferences were noted. Kruskal-Wallis and Mann-Whitney U tests were performed to compare the results. No significant differences were found between the two groups in the MBPS and WBFPRS scores, and mean heart rate changes (P>.05). However, 68 percent of the children preferred ICS. Both ICS and 10 percent lidocaine pump spray presented the same efficacy in reducing injection pain.