The effect of Pink Pigmented Facultative Methylotrophic (PPFM) bacteria as a bio-stimulant on vegetative growth, macro-nutrient elements ( N,P and K ) contents , chemical constituents and volatile oil percentage and components in rosemary plant (Rosmarinus officinalis L.) were studied during 2018 and 2019 seasons. Plant height (cm), number of lateral branches/plant, herb fresh & dry weights and root fresh & dry weights of rosemary plant were all greatly affected with all applied treatments of PPFM when compared with the control. The hugest effect was recorded by 1% PPFM bacteria spraying in both studied seasons. However, no significant effect was recorded due to PPFM applied treatments on P%. Highest values of total carbohydrates were recorded by both 1 and 3%. PPFM bacteria spraying in both studied seasons. Whereas, the highest values of C/N ratios were obtained with 3% PPFM in first season and 1% PPFM in the second one. A substantial effect from PPFM bacteria spraying was observed through its effect on reducing the level of NO3 and NO2 in rosemary herb when compared with the control. In any case, 3% of PPFM bacteria spraying was more effective than other treatments in recording the least values of NO3 and NO2 in first season compared to the control. Volatile oil % was enormously increased with 3% PPFM bacteria spraying in both studied seasons than other treatments or control. The main components of volatile oil of rosemary plant were Camphor, Eucalyptol, Verbenone, Borneol, Pinene, Pinanone, Bornyl acetate and Camphene. The treatments of PPFM bacteria spraying immensely stimulated the component % in volatile oil of rosemary herb than in the control. It could be concluded that the application of PPFM bacteria as foliar spraying in rosemary plant production had many advantages especially reducing NO3 and NO2 levels and increasing volatile oil % and volatile oil fractions not to mention it increased the percent of active ingredients.