Statistical optimization of flows is carried out for a Hall electrolytic conductivity detector (HECD). Yates' method was used to quickly estimate main factors affecting HECD response to organochlorine. Also, more detailed evaluation of variations of HECD response for three flow variables was performed via central composite design factorial experiments. Corresponding three-factor, three-level factorial experiments provided data for least-squares regression analyses. The resulting fitted-polynomial yielded an appropriate mathematical model of the HECD response surface for the corresponding three dimensions in flow-space. Optimum values for three detector flows are thereby selected from the response surface to provide maximum HECD sensitivity, i.e., response to organochlorine in the halogen mode. Supplemental data then allow for flow optimization with respect to other criteria, e.g., signal-to-noise ratios and resolution of eluates.