In this study a new method for the electrochemical determination of Hg(II) ions using N-pchlorophenylcinnamohydroxamicrnacid (CPCHA) modified carbon paste electrode has beenrndeveloped. The experiments were carried out using square wave anodic stripping voltammetryrn(SWASV). The Hg(II) was accumulated on the electrode surface by the formation of therncomplex in an open circuit and the resulting surface was characterized by medium exchangernfollowed by electrochemical reduction and SWASV for the determination of Hg(II).rnExperimental parameters, including carbon paste composition, pH and concentration ofrnaccumulating and stripping solutions, preconcentration time, Hg(II) concentration and differentrninstrumental parameters were investigated. The optimum voltammetric response was observedrnfor a paste composition of 7.5% w/w (CPCHA to graphite powder in the carbon paste) andrnpreconcentration time of 210 s in 0.1 M sodium acetate at pH 8 followed by electrochemicalrnSWASV in 0.3 M ammonium chloride solution at pH 4 as supporting electrolyte, a reductionrnpotential of -0.6 V with 60 s reduction time. Under these optimal experimental conditions, thernvoltammetric signals were linearly dependent on the Hg(II) concentration in the range of 1-25rnÎ¼M with a detection limit of 12.9 nM at the signal noise ratio (S/N = 3). For six measurements,rnthe voltammetric response was reproduced with 3.8% relative standard deviation (RSD) at 15rnÎ¼M Hg(II). Rapid and convenient renewal allows the use of a single modified electrode surfacernin multiple analytical determinations over several weeks. Many coexisting metal ions had little orrnno effect on the determination of Hg(II). Five â€œspikedâ€ samples of water were evaluated by usingrnthe developed method giving recoveries of Hg(II) in the range 98-105%.