Hexahydrated Magnesium Chloride or Bischofite is a salt. It has different properties that enable it to be useful as a chemical stabilizer of granular road surfaces: its capacity of absorbing and retaining humidity from its surrounding environment, increases water surface tension and decreases its vapor pressure. The objective of this research was to evaluate Bischofite performance as a chemical stabilizer of granular road surfaces. Research was based on laboratory tests and the evaluation of test road sections of granular road surfaces stabilized with Bischofite in arid and semi-arid zones of Chile. In general, the field trial results have been more conclusive than the laboratory tests. The use of Bischofite creates a stable granular road surface, reduces potholes, corrugations, erosion and dust emissions, and improves the riding quality.