The hydrolysis of acetohydroxamic acid (AHA) was investigated both in the absence and presence of ferric ions at the range of temperatures (293–333 K). The data were then analyzed using a previously published mathematical model to determine the Arrhenius factor (A) and activation energy (Ea) of the hydrolysis reactions of free AHA and AHA bound to iron in the form of the monoacetohydroxamatoiron(III) complex. The Arrhenius factor and activation energy were found to be 4.24 9 109 dm3mol-1s-1 and 80.1 kJmol-1 respectively for the hydrolysis of free AHA in solution and 2.44 9 1011 dm3mol-1s-1 and 89.6 kJmol-1 respectively for the hydrolysis of ironbound AHA, suggesting a difference in the mechanism for the hydrolysis of the free and complexed ligand. This was further investigated using quantum mechanical calculations.