Cashew nut shell liquid (CNSL), a byproduct of cashew nut processing industry contains mainly cardanol, a meta substituted phenol. Cardanol has been widely used as a synthon for the preparation of number of polymers and industrial products. p -sulphanilic acid and p-anisidine have been diazotised and coupled with cardanol to produce diazotised-p-sulphanilic acid cardanol dye and diazotised-p-anisidine cardanol dye respectively. They have been characterized by UV, FT- IR and 1H-NMR spectroscopic techniques and their antibacterial activity has also been studied and reported for the first time.