Polar as well as nonpolar extracts of Spergula arvensis (corn spurrey) were shown to cause inhibition of seed germination. The polar methylene chloride extracts were subjected to solvent partitioning and separations by a combination of silicic acid and Sephadex LH-20 column chromatography. All chromatographic fractions were monitored by a proso-millet seed germination assay, which resulted in the isolation of a group of sucrose esters (SE). The identity of the ester acids was determined by gas chromatography (GC) of their butyl esters. Further characterization of the SE by GC-mass spectrometry of their trimethylsilyl derivatives showed the presence of four different SE groups with two to seven acyl groups attached to sucrose. The SE isomers in greatest abundance contained either octanoic or dodecanoic acid along with two smaller branched-chain acids (butanoic and pentanoic acids). All four SE groups were inhibitory to seed germination. This is the first report of SE outside the family Solanaceae.