Abstract Variation in the quantity and quality of the essential oil of Artemisia scoparia Waldst. et Kit at different developmental growth stages including vegetative, floral budding and flowering are reported. The oils were obtained by hydrodistillation of air-dried samples. The yields of oils (w/w %) in different stages were in the order of: flowering (0.9%)> floral budding (0.7%)> vegetative (0.4%). The oils were analyzed by GC and GC/MS. In total, 25, 23 and 18 constituents were identified and quantified in the oils of vegetative, floral budding and flowering plants, representing 98.4 %, 98.5% and 98.7% of the oils, respectively. α- and β-Thujone and 1,8-cineole were the main compounds in all samples. α-Thujone, was lower in the vegetative stage and increased in the subsequent harvesting times to reach maximum in flowering. In contrast, β-thujone, was higher in the vegetative stage and decreased during flowering. Oxygenated monoterpenes were the main group of compounds in flowering (97.9%), floral budding (96.6%) and vegetative (93.4%) stage.