The mechanism and mitigation of top of the line corrosion (TLC) is still an on-going research interest because of their consequences on pipelines transporting wet gas. The use of conventional corrosion inhibitors have been very effective in protecting bottom of the pipelines but insufficiently transported to 10-2 o’clock position of the pipes leading to continuous corrosion process at the upper part of the pipe. Therefore the use of volatile corrosion inhibitor has been encouraged because of their low molecular weight and high vapour pressure which makes it easier to be transported to the upper part of the pipe to reduce corrosion rate. The efficiency of methyl di ethanol amine (MDEA) and mono ethylene glycol (MEG) as volatile corrosion inhibitors have been simulated in the laboratory using two-electrode electrochemical cell configuration in CO2 and acetic acid environments (with addition of volatile corrosion inhibitors). There is a progressive reduction in corrosion rate with time in CO2 environment due to the formation of protective iron carbonate film on the metal surface which reduces further corrosion process. Presence of acetic acid changes the corrosion mechanism which resulted in formation of porous and non-protective iron acetate that further increases the corrosion rate due to the solubility of the complex iron acetate in acidified water. Addition of either MDEA or MEG volatile corrosion inhibitor further decreases the corrosion rate in CO2 environment. However both inhibitors are ineffective in acetic acid containing environment. It could be established that the presence of acetic acid breaks down the protective iron carbonate film which are difficult to be re-formed with the addition of volatile corrosion inhibitors.Key words: top of the line corrosion volatile corrosion inhibitors acetic acid pipelines