Abstract In this study, an optimization methodology was developed to obtain design parameters for a frontal occupant impact protection problem using a statistical approach. The central composite design was applied to occupant simulations. On the basis of the design, a total of 25 simulations were performed. The second-order multiple regression injury functions about the head injury criterion (HIC), 3 ms chest acceleration, chest deflection, and right and left femur loads were constructed with high coefficient of determination values and statistical significance (r2 > 0.8 and p 0.001). Then, the response surface method (RSM) was applied to this multicriterion optimization problem, and optimum design parameters about the airbag vent characteristics, triggering time, mass flowrate and knee foam stress-strain relationship were obtained. After the optimized design, the 3 ms chest acceleration, right and left femur loads were reduced by 25.5, 7.1 and 19.9 per cent respectively. These results suggest that the proposed method is useful and effective for automotive safety design problems.