A simple, fast, sensitive and fully validated differential pulse polarographic ( DPP) method for the determination of trace amounts of moxifloxacin in pharmaceutics, serum and urine is reported. Moxifloxacin exhibited irreversible cathodic peak over the pH 5.00 - 11.00 in Britton - Robinson ( B - R) buffer. At pH 10.00 ( the analytical pH), a well-defined peak at -1.61 V versus saturated calomel electrode was obtained. The current has been characterized as being diffusion-controlled process. The diffusion current constant (i(d)) was 1.48 +/- 0.12 and the current - concentration plot was rectilinear over the range from 5 x 10(-7) to 1 x 10(-4) M with correlation coefficient (n = 10) of 0.995.