Tenormin was investigated as corrosion inhibitor for 304 stainless steel (SS) in hydrochloric acid solutions by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. The results showed the variation in inhibition performance of the inhibitors with varying concentrations and temperatures. The maximum efficiency was found to be 92.23 % at 300 ppm concentration of Tenormin drug for the immersion period of 3 hours. Langmuir was tested to describe the adsorption behavior of Tenormin on 304 SS surface. Potentiodynamic polarization study clearly revealed that Tenormin acts as mixed type inhibitor. The results of the electrochemical impedance study showed a decrease in double layer capacitance and increase in charge transfer resistance. The results of various electrochemical techniques show good agreements with each other.