This study was aimed to determine the effects of 24-eBL, a steroid growth regulator, on the plant growth, total phenolic content, essential oil content and composition in “Munstead” lavender cultivar belonging to Lavandula angustifolia. For this aim, 24-eBL was applied to plants at four different concentrations (0, 0.75, 1.50 and 2.25 mg/l) twice, at the beginning of budding and 10 days after the first application. The plants harvested during the full bloom period were evaluated for fresh and dry stemmed flower yields, stemless dry flower yield, total phenolic content and essential oil yield and composition. As a result of the study, 24-eBL at concentrations of 0.75 and 1.50 mg/l significantly increased the stemless dry flower yield, total phenolic content and essential oil yield per plant. 24-eBL applications also changed essential oil composition. To conclude, 24-eBL applications can be used to increase the dry flower yield, phenolic and essential oil contents in lavender plants.