The following chromium(III) complexes with serine (Ser) and aspartic acid (Asp) were obtained and characterized in solution: [Cr(ox) 2 (Aa)] 2-(where Aa = Ser or Asp), [Cr(AspH -1 ) 2 ] -and [Cr(ox)(Ser) 2 ] -. In acidic solutions, [Cr(ox) 2 (Aa)] 2-undergoes acid-catalysed aquation to cis-[Cr(ox) 2 (H 2 O) 2 ] -and the appropriate amino acid. [Cr(ox)(Ser) 2 ] -undergoes consecutive acidcatalysed Ser liberation to give [Cr(ox)(H 2 O) 4 ] ? , and the [Cr(Asp) 2 ] -ion is converted into [Cr(Asp)(H 2 O) 4 ] 2? . Kinetics of these reactions were studied under isolation conditions. The determined rate expressions for all the reactions are of the form: k obs = a ? b[H ? ]. Reaction mechanisms are proposed, and the meaning of the determined parameters has been established. Evidence for the formation of an intermediate with O-monodentate amino acid is given. The effect of the R-substituent at the a-carbon atom of the amino acid on the complex reactivity is discussed.