Groundwater quality in mountainous regions is receiving growing attention due to its importance as a primary source of drinking water. This chapter systematically reviews the available literature on groundwater suitability for drinking purposes in Himachal Pradesh. Situated in the tectonically active Western Himalayas, the state faces persistent water scarcity alongside increasing quality concerns. The review reveals that groundwater in several regions is unsuitable for human consumption, posing serious risks to public health. Contaminants such as fluoride, radon, uranium, nitrate, and toxic heavy metals are frequently reported to exceed the maximum permissible limits set by the World Health Organization (WHO). The study underscores the urgent need for comprehensive, district-wide groundwater quality assessments. It also identifies critical knowledge gaps and finally offers recommendations to address these challenges while directing future research toward sustainable water management.