Arsenic (As) is ubiquitously prevalent in organic and inorganic forms in the environment. Inorganic arsenic is classified as Group I carcinogen to both humans and animals. It is causing contamination of water, air, and soil, which has led to chronic arsenicos is as a newly-emerging public-health issue. Acute or chronic exposure of arsenic through groundwater endangers the health of more than 100 million people worldwide specially the residents of the densely populated Indo-Bangladesh Gangetic delta. Microbial reduction of iron oxyhydroxide(FeOOH) that causes major arsenic pollution in the plains of Ganges-Meghna-Brahmaputra Rivers has also been discussed. Long–term exposure to arsenic can cause skin lesions, cancer, pulmonary diseases, cardiovascular diseases, neurotoxicity, and memory loss. Several experimental studies performed in Zimapan, Mexico have shown high concentration of inorganic As in BECs, which can be used as a marker for cancer. With more stringent regulations, arsenic content requires to be reduced to a few parts per billion. Various techniques are being developed to provide arsenic-free drinking water like membranes, coagulation, anion exchange, disposable iron media, softening etc. Several natural methods like bioremediation and phytoremediation are also being widely used.