A pot experiment was conducted in the screen of the National Research Centre to study the effect of foliar application of cysteine and nicotineamide on the growth and chemical constituents of lavender plants (Lavandula angiostifolia L.). The results indicated that foliar application of cysteine, nicotineamide or their combinations enhanced the vegetative growth of lavender plants, especially when plants were sprayed with cysteine (100 mg/l) combined with nicotineamide (100 mg/l). Data also show that foliar application of cysteine (100 mg/l) combined with nicotineamide (100 mg/l) significantly increased total sugars, total proteins, essential oil percentage and yield. On the other hand, cysteine (50 mg/l) combined with nicotineamide (100 mg/l) resulted in the highest content of linalool, linalyl acetate and geraniol in lavender volatile oil.