Field operating conditions are simulated in the laboratory by controlling flow pressure temperature as well as compositions of material (e.g. carbon steel) oil phase water phase and gas phase. Based on comparison of field and laboratory corrosion rates rotating cage rotating cylinder electrode and jet impingement have previously been identified as suitable for simulating field operating conditions.Standards (ASTM G170 G184 G185 G202 and G 208) on these three laboratory methodologies have been developed. Using procedures prescribed in these standards corrosion inhibitors can conveniently and reliably be evaluated in the laboratory.As part of developing ASTM Standard G202 rotating cage round robin tests have recently been completed in ten laboratories in Canada India USA and Venezuela. These round robin tests have established corrosion rate in the absence of any corrosion inhibitors. Using the round robin test data as baseline the efficiency of various corrosion inhibitors can be established.This paper presents various standards to evaluate corrosion inhibitors for oilfield and refinery applications describes best practices to establish reproducibility of test results in the laboratories and specifies procedures to select appropriate corrosion inhibitor for a particular condition.