The densities, relative viscosities and surface tensions of some selected cardanol based azo dyes were determined. The sodium, ammonium and diethanolamine salts of the respective dyes were successfully synthesized after selective sulfonation. All these compounds were studied and characterized using Fourier Transform Infrared Spectroscopy (FTIR), Liquid chromatography–mass spectrometry (LCMS), UV-Visible Spectroscopy and Nuclear Magnetic Resonance (NMR) spectroscopic techniques. The densities and surface tensions of all the cardanol sulfonate salts were in the range 0.947 g/mL and 32.15–36.79 dynes/cm respectively. The relative viscosities were in the range 1.272 – 1.484.