The genotoxic effects of ascorbic acid, benzoic acid, citric acid, and sorbic acid have been searched in vitro with CBMN technique in human peripheral blood lymphocytes. The purpose of this study was investigated micronuclei, nucleoplasmic bridges and nuclear buds formations, which were caused by test materials in lymphocyte cells of which preparation was made, have been analyzed and cytokinesis-block proliferation index values have been calculated. Lymphocyte cultures have been treated in 24 and 48 hours period with 1000, 500, 250 and 100 mu g/ml material doses of ascorbic acid, benzoic acid, citric acid and sorbic acid. According to the results that have been obtained from CBMN, doses of 1000 mu g/ml of benzoic acid and citric acid and 1000 and 500 mu g/ml doses of sorbic acid are cytotoxic effect. All doses of ascorbic acid have been observed no cytotoxic and genotoxic effect. 500 and 250 mu g/ml concentrations of citric acid, benzoic acid and 250 mu g/ml concentrations of sorbic acid induced micronucleus formation statistical significantly at 24 h and 48 h, and 100 mu g/ml concentrations of citric acid-induced micronucleus formation statistical significantly at 48 h, when compared with solvent control values. Ascorbic acid, benzoic acid, citric acid, and sorbic acid decreased the cytokinesis-block proliferation index depending on the increase in concentration; however, this reduction in cytokinesis-block proliferation index values was not statistically significant. Also, it has been reached to the inference that nuclear buds and nucleoplasmic bridges formation values were found to be not statistically important. It is concluded that high dose of benzoic acid, citric acid and sorbic acid may indicate cytotoxic and genotoxic effect in vitro human blood lymphocytes when they are taken as food additives.