Silver dendrites have been prepared by an electrochemical technique in an aqueous solution of AgNO3 in the presence of DNA. An electrochemical cell was placed in an operating ulrasonic bath and carried out the electrolysis in the presence of an ultrasonic field. Silver dendrites were characterized with a transmission electron microscopy and X-ray diffraction. It was found that the concentration of AgNO3 and DNA affected the formation of the nanoparticles.