Children who are behaviorally "inhibited"--a condition at the extreme of the behavioral inhibition dimension--experience distress in uncertain social situations. Although parents and teachers are in the best position to detect this condition, they rarely agree. This study aims to analyze the agreement between parents and teachers and to examine the relations between ratings made by parents and teachers and assessments made by clinicians and researchers. Parents, teachers and clinicians rated the behavioral inhibition of 365 preschoolers. Seventy-three randomly selected participants were observed using an adaptation of the Behavioral Inhibition Paradigm. Parent-teacher correlations on 34 items and different clusters were, on average, r = 0.3. The degree of convergence between observational measures and ratings by parents and teachers was moderate-low and did not improve when considering only subsamples from the ends of the distributions. Discriminant analysis suggests that both parents and teachers tend to have a moderate-low ability to detect "inhibited" children.