This study represents an electrochemical sensor to determine the hydroxylamine through voltammetry methods based on a screen printed electrode (SPE) modifiedwith La3+-doped Co3O4 nanocubes. The La3+-doped Co3O4 nano-compositewas prepared through an easy chemical reduction technique. The modified SPE presented good electrocatalytic performance toward hydroxylamine oxidation. The limit of detection (LOD) (S/N = 3) and sensitivity were obtained 0.08 mu M and 0.037 mu A/mu M, respectively. The sensor was used for detecting hydroxylamine in (spiked) water samples. (C) 2019 The Electrochemical Society.