Objective The aim of this study was to evaluate the use of the DIAGNOdent system in epidemiological studies to detect noncavitated occlusal caries lesions, and compare the results with those found in radiographic examinations. Methods The sample consisted of 1,290 occlusal surfaces of permanent molars, examined in 179 schoolchildren aged 12-15 years. The methods used were: visual inspection, radiographic examination and DIAGNOdent exam, with radiographic examination being considered the gold standard, and noncavitated caries lesions identified in dentin under sound enamel. The inclusion criterion of this study was to have sound occlusal surfaces on visual inspection. The sensitivity and specificity, positive and negative predictive values were used for statistical analysis. Results: Of the 1,290 surfaces examined during visual inspection, 918 were scored as clinically sound. Of these, 789 were examined by radiographic examination and DIAGNOdent, considering that in more than half of them (410) there were coincident results in the absence of noncavitated lesion in both methods (radiographic examination by DIAGNOdent), with specificity of 74% and negative predictive values of 82% and 155 coincident surfaces with presence of caries, with sensitivity of 64% and positive predictor values of 53% for DIAGNOdent. Conclusion These results suggest that although DIAGNOdent is not a substitute method for the radiographic examination in surveys, it may be an alternative as an auxiliary to visual inspection. Key words: DIAGNOdent, epidemiology, noncavitated occlusal caries, radiographic examination.