To evaluate the effects of bio-fertilizers included; nitrogen fixing bacteria (N-b), phosphate solubilizing bacteria (Pb), sulfur oxidizing bacteria (Sb), N-b+Pb, Nb+Sb, Pb+Sb, N-b+Pb+Sb, chemical fertilizer (chemical origin of nitrogen+ phosphorus+ potassium=NPK) and control (no fertilizer treatment) on the components of essential oil of Dracocephalum moldavica, an experiment was conducted based on randomized complete block design with four replications. Results showed the significant effect of bio-fertilizers on biomass and essential oil percentage and yield. The highest biomass and essential oil yield were obtained by NPK application, followed by biological nitrogen. The highest essential oil percentage was recorded for plants treated with N-b+Pb+Sb treatment, which was statistically similar with plants inoculated by N-b, and Pb+Sb. About 60 components were identified in the essential oil; the major compounds were geranyl acetate, geranial, geraniol, neral, nerol. Geranial was the prominent component found in considerable quantity in all treatments except NPK, in which it was absent.
