Characteristics of unpleasant odor emitted by inflorescences of four gypsophila cultivars (Gypsophila elegans Bied. ‘Covent Garden Market’ and G. paniculata L. ‘Bristol Fairy’, ‘Golan’ and ‘Yukinko’) were investigated by headspace adsorption/gas chromatographic (HA/GC) analysis. The major volatile compounds emitted from ‘Bristol Fairy’ inflorescences were ocimene, 3-methylbutyric acid, 2-methylbutyric acid, ethanol and n-hexanol. Of these volatile compounds, the two methylbutyric acids were identified as the compounds that characterize the unpleasant odor of gypsophila inflorescences. The composition of volatiles varied among cultivars; ocimene was the most abundant and common constituent detected in all gypsophila cultivars. Methylbutyric acids was the highest in ‘Bristol Fairy’ and ‘Golan’ followed by ‘Yukinko’; they were undetectable in non-scented ‘Covent Garden Market’. Methylbutyric acids were not detected in the volatiles emitted from ‘Bristol Fairy’ inflorescences at the bud stage; the emissions increased gradually with bud opening and reached the highest level at the full open stage on day 4.