Response surface methodology (RSM) was used to evaluate the effects of variables, namely the concentration of glucose, citric acid, KH₂PO₄ and NH₄Cl, in the synthetic production medium for xanthan production. Central composite design was used in the design of experiments. The experimental results showed that the optimum concentration of the components were (in g/l): glucose, 34.20; citric acid, 2.11; KH₂PO_4, 4.01 and NH₄Cl, 2.13. The maximum xanthan production was 12.5 g/L.  This method was efficient; only 24 experiments were necessary to assess these conditions, and model adequacy was very satisfactory as the coefficient of determination was 0.9856.