A simple highly sensitive spectrophotometric method was developed for the quantification of Sparfloxacin (5-amino-1-cyclopropyl-7-[(3, 5- dimethylpiperazin-1-yl]-6, 8-difluoro-4-oxo-quinoline-3-carboxylic acid). The method involves the reaction of the target compound with copper sulphate in acetic acid in presence of sodiumnitrite reagent to produce a bluish green color chromogen. The derivative chromogen exhibits absorption maxima at 404 nm. Under this reaction, no degradation occurs. The proposed method can be utilized as a stability indicating assay. The different experimental parameters affecting the derivatization reaction were carefully studied and incorporated into the procedure. Under the described conditions the proposed method is linear over the concentration range of 5-45 mcg/ml and the coefficient of determinationwere >0.999with a relative standard deviation of 0.236%. The average recovery of the target compound is 99.46%with a limit of quantification (LOQ) of 0.293mcg/ml and the limit of detection (LOD) 0.096mcg/ml. Themechanismof the derivatization reaction is proposed and advantages of the proposed method are discussed.