In this study, genotoxic effect of sodium fluoride (NaF) was investigated in Drosophila melanogaster Somatic Mutation and Recombination Test. Third-instar larvae trans-heterozygous for two genetic markers mwh and flr, were treated at different concentrations (2.5 mu g/ml, 5 mu g/ml and 10 mu g/ml) of the test compounds. After the treatment the observed mutations were classified according to size and type of mutation per wing. For the evaluation of genotoxic effects, the frequencies of spots per wing in the treated series were compared to the control group, which is distilled water. NaF has genotoxic and toxic effects for concentrations of 5 and 10 mu g/ml. The present study shows that NaF may have genotoxic and toxic effects. (C) 2009 Elsevier Ltd. All rights reserved.