Inorganic arsenic possesses the highest toxicity threat amongst all its forms found in natural groundwater and its mobility in aquatic systems and in the soil is of great environmental concern. Besides their toxicity to humans, arsenate and arsenite are highly toxic to plants. Arsenic can only be transformed into a less-toxic material and becomes a permanent part of the environment. Thus, there is a continuing need for its monitoring at arsenic-containing sites where it occurs naturally at elevated levels. This report reviews technologies with the potential to measure and monitor arsenic in the environment. However, we focus on the modern electrochemical methods of arsenic detection in drinking water. The pros and cons of such techniques are discussed with respect to their sensitivity, ability to detect the chemical states of arsenic, reliability, potential interferences, and ease of operation. In particular, emphasis has been devoted to more recent topics including modern stripping voltammetry, electrode modification, nanomaterials, and biosensors. The necessity for field instrumentation, detection and monitoring has also been addressed.