Objective: The relationship between cystic fibrosis (CF) and caries experience has already been explored, but relatively little information is available on dental enamel defects prevalence among children affected by cystic fibrosis. The aim of this study was to investigate this issue in deciduous and permanent teeth of children with CF resident in southern Italy. Basic research design: This cross sectional observational study was undertaken between October 2009 and March 2010. Participants: 88 CF patients and 101 healthy age-matched participated in this study. Methods: The prevalence of dental enamel defects was calculated using a modified Developmental Defects of Enamel (DDE) index. The comparison of dental enamel defects prevalence among groups was carried out using regression binary logistic analysis. Results: In the CF subjects there was a higher prevalence (56%) of enamel defects in comparison to the healthy group (22%). The most prevalent enamel defect was hypoplasia with loss of enamel (23% of CF patients vs 1½% of control group) in permanent teeth. Conclusion: This study confirms that children with cystic fibrosis are at increased risk of developing hypoplastic defects on their permanent teeth. Key words: enamel defects, cystic fibrosis, enamel hypoplasia.