Sweet taste administration before dental injections helps to control associated pain in children. To evaluate the efficacy of using a sugar-free flavor on pain perception during dental injections. Children (n = 84) aged 4-9 (mean 6.71 ± 1.55) years who required buccal infiltration bilaterally participated in this split-mouth randomized crossover study. On the test side (flavor visit), infiltration injections were applied after receiving a sugar-free flavor. On the control side (no flavor visit), sterile water was administered. Demographic characteristics, body mass index (BMI), and sweet taste preference (STP) were recorded. Pain perception during injection was measured using heart rate (HR), sound, eyes, and motor (SEM) scale, and Wong-Baker Faces pain scale (WBFPS). Most children had healthy weight (72.6%) and equal STP (32.1%). In the test side, mean HR during injection, HR differences before and during injection, and SEM scores were significantly lower (p < .001, for all). There was no significant difference in the WBFPS between both visits. Flavor had a significant effect on pain reduction (p = .001 for HR, p = .000 for SEM), whereas age, gender, BMI, STP, and treatment side did not. Treatment sequence had a significant effect on total SEM scores (p = .021); children who received the flavor during their first visit had lower SEM scores. Using a sugar-free flavor before dental injections helps in reducing associated pain in children.