A simple and sensitive spectrophotomteric method has been developed for the determination of Sertraline in pharmaceutical and blood sample. The current method is depend upon the reaction between the sertraline and chloranilic acid in slightly alkaline medium, giving a purple colour complex having maximum absorbance at 527.5 nm. The reaction is selective for sertraline with 0.01mg/mL.The colour reaction obeys Beer's law from 0.1mg to 5mg/mL of sertraline and relative standard deviation is 0.19%. The quantitative estimation of sertraline in blood sample is also studied.