OBJECTIVE To correlate the salivary cortisol levels in children attending a university dental clinic with their behavior during the dental appointment. METHODS A prospective study was conducted with 43 seven- to 10-year-old children whose behavior during the dental appointment was assessed using the Frankl scale. Participants were divided into two groups: (1) cooperative children; and (2) uncooperative children. All children had four saliva samples collected as follows: prior to the dental examination (S1); shortly after the dental examination (S2); 30 minutes after waking up in the morning after the day of the appointment (S3); and in the afternoon, 24 hours after the dental appointment (S4). Salivary cortisol levels were measured by the chemiluminescent assay method. Statistical analysis included the Friedman and the Wilcoxon signed rank tests. RESULTS For the cooperative group, salivary cortisol levels were significantly lower at S1 (P=0.004), S2 (P=0.006), and S4 (P=0.001) compared to S3. For the uncooperative group, salivary cortisol levels were significantly higher at S1 compared to S2 (P=0.005). CONCLUSIONS Uncooperative children presented high levels of salivary cortisol prior to and shortly after the dental appointment. The period anticipating the consultation was considered highly stressful.