Lead sulfide quantum dots have been synthesized from a cost- effective and facile chemical method namely ionic reaction using lead nitrate and sodium sulphide as precursors in aqueous solutions. The as prepared nanocrystals are characterized for their optical, structural and electrochemical properties using optical absorption spectroscopy, transmission electron microscopy and cyclic voltammetry respectively. The PbS quantum dots have an average size of 6 nm. The strong size quantization is observed from cyclic voltammetry and absorption spectroscopy.