The rate of hydrolysis of p-nitrophenyldiphenylphosphate in the presence of micellized [Cu(C(12)tmed)(L)](+) where C(12)tmed is N,N,N'-trimethyl-N'-dodecylethylenediamine and L is the anion part of the amino acid has been investigated. It was found that the observed maximum rate obtained under the excess surfactant over the substrate condition depends very much on the ability of the amino acid ligand to form a mixed-chelate complex with the [Cu(C(12)tmed)](2+) moiety. In general, a chelating ligand with better coordination ability gives a slower rate because of the reduction in the supply of Cu-OH nucleophile in the micelle,