1. This study was to evaluate the toxic effects of aflatoxin (AF) on growth performance of quail, and to determine the preventive efficacy of MYCOTOX® (oxicinol, tymol, micronised yeast). 2. One hundred and eighty 1-d-old quail (Coturnix coturnix japonica) of both sexes were weighed and randomly divided into 4 experimental groups each with 5 replicates of 9 birds. 3. There were 4 dietary treatments: (1) control with 0 mg AF/kg diet and 0% MYCOTOX®; (2) 0 mg AF/kg diet and 0·5% MYCOTOX®; (3) 2·5 mg AF/kg diet and 0% MYCOTOX®; (4) 2·5 mg AF/kg diet plus 0·5% MYCOTOX®. The chicks were maintained on these treatments to 3 weeks of age. Quail consumed the diets and water ad libitum. 4. Body weight (BW) gains in groups receiving AF alone were the lowest at all periods. Feed intake was lowest in the group consuming the AF diet. The addition of MYCOTOX® to the AF diet did not prevent or reduce the toxic effects of AF on feed intake at any time period. Feeding diets containing MYCOTOX® alone did not change feed intake significantly. With the exception of the 1 to 7 d period, feed conversion of chicks fed the AF diet was similar to those of the other experimental groups. 5. Bursa of Fabricius weight decreased, whereas the relative weights of liver, kidney and spleen increased in quail consuming diets containing AF and AF plus MYCOTOX®. Liver colour was normal in the control and MYCOTOX® alone group, but was lighter in groups fed AF. 6. The results indicated that MYCOTOX® was not effective in preventing the deleterious effects of AF.