The current research deals with optimisation of the plywood sandwich panels with corrugated core under four point loading conditions. The finite element model has been extensively verified by strain and deflection measurements obtained from physical tests from sandwich panel prototypes. An overall good correlation between experimental and numerical models has been achieved. The metamodelling methodology utilising the design of computer experiments with mean square error space filling criteria and approximation techniques have been used for optimisation task. Approximation functions have been created to predict response values for combinations of variables not included in initial experimental design. A four design variables have been considered, including geometrical dimensions and the veneers lay-up configurations. As response functions the panel strain, deflection and volume responses has been considered. Using metamodelling functions optimal cross section parameters have been elaborated for evaluation of most efficient bending stiffness versus weight ratio. For several panels with optimal cross section parameters design guidelines has been elaborated to overview the capabilities of different geometrical configuration for design of all-plywood sandwich panels.