The 3-hydroxy-2-oxindole core structure is of considerable significance in both synthetic and medicinal chemistry. A novel and efficient base-promoted method for the preparation of 3-hydroxy-2-oxindoles from o-alkynylnitroarenes has been discovered. The reaction could be conducted under transition metal free conditions. Various o-alkynylnitroarenes were checked and the desired products were obtained in moderate to good yields. The Wittig-like reaction triggered by the PPh3 and the subsequent acyloin rearrangement constituted the main reaction process.