Food flavourings are an essential element in foods. Benzyl derivatives are the food additives which are used for increasing the taste of foods and beverages. In this study, different concentrations of four benzyl derivatives (benzaldehyde, benzyl acetate, benzyl alcohol and benzoic acid) used as flavour ingredients have been evaluated for genotoxicity in the wing somatic mutation and recombination test (SMART) of Drosophila melanogaster. Third-instar larvae trans-heterozygous for two genetic markers mwh and flr, were treated at different concentrations (0.1, 0.5, 1, 10, 25 and 50mM) of the test compounds. Wings of the emerging adult flies were scored for the presence of spots of mutant cells, which can result from either somatic mutation or mitotic recombination. Also lethal doses of benzyl derivatives used as flavour ingredients were determined in the experiments. 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. Chemicals used were ranked as benzaldehyde, benzyl acetate, benzyl alcohol and benzoic acid according to their genotoxic effects. The present study shows that intensive administration of benzyl derivatives used as flavouring agents may have a significant genotoxic effects.