Bioassay-guided chemical investigation of the stem bark of Melia azedarach var. Japonica has led to a new limonoid, 12-hydroxyamoorastatone along with two known limonoids 12-hydroxyamoorastatin and 12-acetoxyamoorastatin. The structure of the new compound followed from spectral data and the stereochemistry was determined by NOE experiment on the di-p-bromobenzoate. All three compounds exhibited significant cytotoxicites against five human tumour cell lines.