The composition of essential oils from leaves and flowers of two hybrids (Carlos and Florom 350) of Helianthus annuus cultivated in Tuscany (Italy) was investigated. The compounds were identified using gas chromatography (GC)/mass spectrometry (MS) analyses. Sixty-nine compounds were identified in the essential oils of leaves and flowers of sunflower plants harvested in July. Significant percentage variations were recorded between the leaves and flowers oil content. The monoterpenes were the major compounds present in both essential oils examined. α-pinene content was higher in flowers (72.6%) than in leaves (28.6%). The content of sabinene was ∼2 times higher in leaves than in flowers. There were no significant differences between the essential oil composition of the oils obtained from the same organs of the two hybrids.