Climate change implies a general increase in global temperature, increased frequency and intensity of rainfalls. The combination between increased rainfall intensity and raise in temperature is likely to result in increases in frequency, severity and spatial spread of landslide hazard. Particularly, debris flows can become more common in many parts of the world. Debris flows are a mixture of granular materials and water which behaves as a moving continuum as a result of gravity. The sliding mass has high water content and hence a large speed and can remove and/or destroy lives, buildings and infrastructures along its way. This poses a significant threat to human life, health, well-being and financial loss for individuals, businesses and society. This article presents the results from laboratory tests of model debris flows hitting against deflection walls as a preventative measure. The purpose is to study the effect of using deflecting walls in mitigating debris flow hazard. In particular, the study examines the dependency of the run-up height of the debris mass after hitting the walls on the deflection angle and the inclination angle of the walls. Some shortcomings of the existing model are also discussed in order to improve future studies.