Abstract A study of the chemical composition of essential oil of the oriental tobacco Yaka was performed using GC and GC/MS. The major constituents in oil were solanone (29.5%) and neophytadiene (23.0%). The antimicrobial activity of the oil was investigated in vitro by the disc diffusion method. The oil showed noticeable activity against Escherichia coli, Staphylococcus aureus and Pseudonumas aeruginosa.