Arsenic (As) is a poisonous metalloid and recognized as a Group I human carcinogen by the International Agency for Research on Cancer (IARC). Arsenic often exists in groundwater and surface water, oceanic and inland deposits, rocks, soils, and biota at variable concentrations. Over the last few decades, As contamination has been augmented noticeably due to both natural and anthropogenic sources. Arsenic contamination in groundwater is currently a major global environmental catastrophe, which affects over 200 million people in 107 countries and causes various health complications including cancer. Therefore, updated information regarding the sources, chemical form, bioavailability, extent and severity, food safety and regulation, remediation, and management of As is essential. In this chapter, we accumulated the detailed sources of As, including point and diffuse sources, various inorganic and organic As species, and their toxicity in the environment. Moreover, the fate of As in the environment, economic implications of As-contaminated food and food products, and the bioavailability and bio-accessibility of As in environmental media are also briefly summarized. Remediation technologies for As-contaminated soil with the latest case study and regulatory limits of As in soil are also presented in this chapter. Overall, this chapter incorporates the past and contemporary knowledge of As, which will be useful for better management of As in the near future.