This paper presents an electrochemical quartz crystal nanobalance (EQCN) and scanning electron microscopy study conducted to better understand the inhibitor film formation and destruction processes in pipelines. The kinetics of the inhibitor film formation and destruction processes were investigated through the laboratory-scale EQCN experiments. The results of this study demonstrate that the EQCN is a promising alternative to the macroscale methods that have been commonly used to study inhibitor persistency. Scanning electron microscopy results show that corrosion of specimens protected with an inhibitor film was due to pitting corrosion mostly concentrated around the flow cell inlet. Specimens on which a protective inhibitor film did not develop exhibited uniform corrosion. Energy-dispersive X-ray spectroscopy results show that chlorine accumulation only occurs inside the pits.