Escitalopram oxalate (EO) is considered as one of the extensively prescribed antidepressant drug in Turkey and some other countries, therefore this research was aimed to study the interaction of the drug with DNA and study of the substance effect on bacterial growth. The absorption value of the drug solution at 238 nm was increased when DNA was added gradually to it and it showed hyperchromism effect. The value obtained for DNA binding constant (Kb) was 0.035 M-1. When we added the CuCl2 2H2O to the mixture, any breakage was not shown in double strand DNA in comparison with control DNA. In addition low concentration of EO couldn't protect DNA (0.5273 mu mole bp) against Hydroxyl free radical (0.12 mu mole) although it could protect the DNA when it was at the same or higher concentrations (0.5273, 5.273 and 252.73 mu mole) than the DNA concentration. In addition, MIC of the drug for E.coli and Bacillus subtilis was almost 0.185 mM and 0.55 mM respectively. The E.coli strain was killed at concentrations 45, 15, 5 mM while the Bacillus subtilis was stable against all of the concentrations.