AbstractSingle crystals of tungstenite (WS2) have been grown by direct vapour transport or sublimation method. An etchant capable of revealing the sites of dislocations has been developed. The effects of etching time, etchant concentration and temperature on the selective etch rate have been worked out. It is seen that the etch rate is independent on time, but is influenced by the temperature and concentration of the etchant. The values of activation energy determined from the etch rate against temperature plots established that the process of etching in chromic acid is chemical reaction rate controlled. The effect of addition of HF to the above etchant has led to some further interesting results.