Geogenic contaminants Arsenic and Fluoride threaten the wellness of groundwater worldwide. These pollutants enter groundwater in several ways, either from natural or anthropogenic sources. Though groundwater is a crucial resource for over 2.5 billion people worldwide, human society's main concern is providing good-quality drinking water. A high human health risk could result from the high percentage of As and F contaminants in groundwater. In the last decade, there have been a huge number of reports on groundwater contamination by arsenic and fluoride from Southeast Asian countries (Bangladesh, China, India, etc.) as well as a few recently impacted areas in other countries. This chapter examines the current situation about arsenic and fluoride contaminations of groundwater in different parts of the world, as well as the environmental impact assessment (occurrence and co-occurrence) and recommends appropriate remedies for various spatial concentration zones.