The chemical compositions of 20 Algerian Daucus gracilis essential oils were investigated using GC-FID, GC/MS, and NMR analyses. Altogether, 47 compounds were identified, accounting for 90 - 99% of the total oil compositions. The main components were linalool (18; 12.5 - 22.6%), 2-methylbutyl 2-methylbutyrate (20; 9.2 - 20.2%), 2-methylbutyl isobutyrate (10; 4.2 - 12.2%), ammimajane (47; 2.6 - 37.1%), (E)-β-ocimene (15; 0.2 - 12.8%) and 3-methylbutyl isovalerate (19; 3.3 - 9.6%). The chemical composition of the essential oils obtained from separate organs was also studied. GC and GC/MS analysis of D. gracilis leaves and flowers allowed identifying 47 compounds, amounting to 92.3% and 94.1% of total oil composition, respectively. GC and GC/MS analysis of D. gracilis leaf and flower oils allowed identifying linalool (22.7%), 2-methylbutyl 2-methylbutyrate (18.9%), 2-methylbutyl isovalerate (13.6%), ammimajane (10.4%), 3-methylbutyl isovalerate (10.3%), (E)-β-ocimene (8.4%) and isopentyl 2-methylbutyrate (8.1%) as main components. The chemical variability of the Algerian oil samples was studied using statistical analysis, which allowed the discrimination of three main Groups. A direct correlation between the altitudes, nature of soils and the chemical compositions of the D. gracilis essential oils was evidenced.