A simple and sensitive spectrophotometric method has been developed for the determination of arsenic using variamine blue as a chromogenic reagent. The method is based oil the reaction of arsenic(III) with potassium iodate in acid medium to liberate iodine, which oxidizes variamine blue to form a violet coloured species having an absorption maximum at 556 nm. Beer's law is obeyed in the range 0.2-14 mu g mL(-1) of As(III). The molar absorptivity, Sandell's sensitivity, detection limit and quantitation limit were found to be 1.43 x 10(4) L mol(-1)cm(-1), 5.26 x 10(-2) mu g cm(-2), 0.022 and 0.072 mu g mL(-1), respectively. The optimum reaction conditions and other analytical parameters were evaluated. The proposed method has been Successfully applied for the determination of arsenic in various environmental and biological samples.