The inhibition efficiency of Zn2+, 3-phosphonopropionic acid (3-PPA), benzotriazole (BTA) and two synthesized benzotriazole derivatives namely 1-(2-pyrrole carbonyl) benzotriazole (PCBT) and 1-(2-thienylcarbonyl) benzotriazole (TCBT) were evaluated as inhibitors for the corrosion of mild steel in ground water. The inhibition efficiencies of PCBT and TCBT in combination with Zn2+ and 3-PPA were also investigated and the results were compared with BTA. In order to study the corrosion rate and inhibition efficiency we employed potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Further characterization using Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) demonstrates the adsorption of inhibitor and the formation of corrosion products on the mild steel surface, respectively. Combination of PCBT along with Zn2+ and 3-PPA shows better corrosion inhibition efficiency than other inhibitor combinations and the individual inhibitors.