The dependence of ethanol production by fermentation using Saccharomyces cerevisiae 251 TP(3-2) on zinc, sodium and potassium ion concentration was studied with the use of a statistical experimental design. The parameters of the ethanol concentration model proposed on the basis of the Box-Wilson experimental design method were evaluated using the experimental data. Comparison of the predicted values from the model with the experimentally observed values showed that the model is a good fit. From analysis of the model equation it was seen that zinc, sodium and potassium ion concentrations have significant main effects on ethanol production but there were no interactive effects of the ions. Using the developed model, the maximum ethanol concentration of 4.19% (v/v) was obtained when potassium, sodium and zinc concentrations were 7900, 930 and 3.04 mg L-1, respectively. (c) 2007 Society of Chemical Industry