This work aims at optimizing a helmet. First a discrete dynamic model of a helmet has been proposed for modeling the free fall of the helmet from a height of 2m. The model was solved using Runge Kutta method. The time history of head acceleration has been extracted from this solution and ‘Time bound peak acceleration criteria’ of head injury has been computed After preparing the model it was validated using available experimental and FEM results. The model was then used for optimization. The objective of optimization is to minimize ‘time bound peak acceleration’ which is taken as an injury criterion representing the effectiveness of the helmet. The optimization is constrained to a maximum total mass and total thickness of the helmet. The optimization has been carried out using conventional method as well as genetic algorithms. Subsequently the sensitivity of the objective function with respect to different design parameters was studied. © 2006 by CAD Solutions.