Inverse techniques based on vibration tests and numerical calculations are sensitive to model errors, which bring discrepancies in the results of the estimated parameters. In the present study model errors related to geometrical simplifications of laminated plates were investigated experimentally. The investigation focused on the effect that the model errors had on identified material properties. The inverse technique based on the design of experiments and response surface methodology was used in the identification procedure. Eigenfrequencies of the plate mostly affected by the model errors were eliminated from the objective function reducing the estimation error of the identified material properties.