The corrosion inhibition performance of synthesized inhibitor 7-bromopyrido[2,3-b]pyrazine-2,3(1H,4H)-dithiol (M₂) was investigated on mild steel corrosion in 1 HCl using gravimetric and electrochemical measurements. The studied inhibitor, M₂showed the maximum inhibition efficiency (E) of 91% at a concentration as low as 10^-3M. The potentiodynamic polarization studies showed that the studied inhibitor (M₂) act as mixed inhibitor. The results of EIS studies showed that in the presence of inhibitor M₂, transfert charge resistance increased and Cdl decreased due adsorption of inhibitor at the mild steel surface. The adsorption of inhibitor molecules on mild steel surface obeys the Langmuir adsorption isotherm. The results of the theoretical investigation and experimental studies well complimented each other.