From last 20 years survey in the Ganga-Meghna-Brahamaputra plain (area 569749 sq km; population >500 million) analyzing around 2,11,000 water samples we have found, a good portion of the states and countries (Uttar Pradesh, Bihar, Jharkhand, West Bengal, Assam and Bangladesh) is arsenic affected (>50 μg/L). Screening more than 1,50,000 people from affected villages about 15000 patients were registered with different kinds of arsenical skin lesions. Arsenic neuropathy aswell as adverse pregnancy outcomes such as spontaneous abortion, still birth, preterm birth and low birth weight was recorded. Infants and children drinking arsenic contaminated water are at high risk. About 50,000 biological samples analysis from arsenic affected areas showed elevated level of arsenic in both patients and non-patients indicating many are sub clinically affected. Proper watershed management, economical utilization of available surface water, and the participation of all who live in or have influence over the region are needed for mitigating the situation. © 2008 Taylor & Francis Group, London, UK.