Void detection is a difficult task for geophysical methods. The main disadvantage is the uncertainty of the final interpretation and the need for verification of the results with direct methods of underground investigation. A good way to reduce this uncertainty, apart from drilling, is through the implementation of more than one geophysical method in the same area. An integrated approach of geophysical methods can be achieved by using multiparameter statistical techniques, such as cluster analysis. Firstly, the effectiveness of multiparameter analysis on synthetic data is studied and then on real data from a controlled test site. In addition, a new approach for the creation of a unified geophysical model (UGM) is suggested to optimize target detection. Finally, the UGM approach is implemented and is evaluated in a real case study for void detection in an urban environment. The UGM offers the integrated information of the geophysical methods that are used without the need for predefined relationships. It is a model resulting from a specific statistical procedure, free of subjective precautions, and easily understood even by nonexperts in geophysics. Finally, it offers an additional tool for the better understanding of the subsurface as far as the difficult task of void detection is concerned.