Abstract: A simple spectrophotometric method for the determination of citrate in urine is described. This method is based on the complexation of Cu(II) with the Citrate at an elevated pH, which results in the formation of blue colored bis-citrate-Cu(II) complex, measured at 760 nm. The method is applied to the determination of low level of citrate in the urine sample. The relative standard deviation (RSD) was more than 1.5% in the range investigated. The urinary citrate level in 100 stone formers had a median value of 0.78 mM while in the control group the median value of citrate has been 1.3 mM.