Alkanolamines such as monoethanolamine (MEA) in aqueous solution are commonly used for scrubbing of acid gases. High concentrations of alkanolamine waste can be generated from natural gas processing plants which may be difficult to treat in a conventional biological treatment unit. In this paper, chemical pretreatment of MEA using Fenton’s reagent prior to biological treatment was investigated. The results showed that COD removal via Fenton’s oxidation was highly dependent on initial MEA concentration with 54.5% COD removal at the highest initial MEA concentration used. Glycine was identified as a degradation by-product in the partially degraded MEA which was observed by HPLC and FTIR techniques. The aerobic biodegradability of partially degraded MEA (after 40% COD degradation by Fenton’s reagent) compared to untreated MEA was investigated using batch mixed-culture experiments to determine the kinetic coefficients for aerobic biological treatment. The results showed that biodegradability of the partially degraded MEA was improved compared to untreated MEA based on the kinetic constants and reduced acclimatization time. Dissolved ammonia was also found to be formed in significant amounts during both Fenton’s oxidation and biological oxidation.