Abstract Background: The quantification of fluorosis using fluorescence imaging (QLF) hardware and stain analysis software has been demonstrated in selected populations with good correlation between fluorescent image metrics and TF Index scores from photographs. The aim of this study was to evaluate the ability of QLF to quantify fluorosis in a population of subjects (aged 11-13) participating in an epidemiological caries and fluorosis survey in fluoridated and non-fluoridated communities in Northern England