© 2015 Australian Dental Association. Background This study examined water fluoride levels at schools across Western Australia. The aim was to identify schools where levels of water fluoride appeared to be below dental health thresholds (0.5-1.0 mg/L) as recommended by the National Health and Medical Research Council (NHMRC). The objective is to provide health organizations with the knowledge for a more targeted approach to schools with greater risk of decay. Methods Population data, school location, enrolment data and water quality data were integrated into geographic databases for analysis using Quantum GIS, Lisboa 1.8. Results The results indicated that 46% of school attendees in the northern half of Western Australia were at schools where there was the potential that the water was not dentally optimally fluoridated while in the southern half of Western Australia this was about 10%. Of these attendees (north and south), 45% were at primary school. Similarly, there was an association between socio-economic decile and proportion of school attendees in non-dentally optimally fluoridated schools. Lower deciles (i.e. poorer attendees) had a greater risk of being in schools outside dentally optimally fluoridated areas. Conclusions This study clearly highlights areas where more prevention (and probably) treatment needs are present and provides a framework for targeted service planning.