Objective: To investigate the influence of different settings, epidemiological and clinical, and different diagnostic thresholds on caries detection in a group of 7-10-year-old children in Brazil. Materials and Methods: In total, 983 children aged 7-10 years old and enrolled in four public schools were randomly selected. Three examiners performed epidemiological examinations followed by an examination of the same children in a clinical setting. The examinations of cleaned and dried teeth in both settings were carried out using a dental mirror and ball-ended probe, under natural light in the epidemiological setting examinations and under artificial light during the clinical setting examinations. For the analysis of results, comparisons were focused on WHO (World Health Organization) diagnostic thresholds versus WHO+IL (initial lesions) diagnostic thresholds, both under epidemiological conditions, in order to demonstrate the influence of the inclusion of IL in the study; and WHO+IL in the epidemiological setting versus WHO+IL in the clinical setting, aiming to demonstrate the importance of examination setting. Outcome measures were dmfs, DMFS, ds, Ds, sealants and number of children 'free' of caries. Paired t-test and McNemar's test were used to test the difference between means and proportions for each age group. Results: Epidemiological examinations, under the WHO diagnostic threshold, showed significant differences for all outcome measures when compared with the WHO +IL threshold. Statistical differences were also detected when comparing the WHO+IL threshold under different settings. Conclusion: The choice of a diagnostic threshold (WHO or WHO+IL) and the conditions of examination (epidemiological or clinical) were important for caries detection. Keywords: dental caries, diagnosis, epidemiology