The chemical composition of the essential oil obtained by hydrodistillation of the dried aerial parts of Pelargonium graveolens L. collected from the region of Khenifra (central Middle Atlas of Morocco) was studied by gas chromatography coupled with mass spectrometry which has enabled us to identified 54 constituents representing (99.99%). The major components are Geraniol (31.01%), Citronellol (29.52%), Linalool (10.50%), Citronellyl formate (9.06%), Geranyl formate (5.75%), and iso- Menthone (2.86%) with a total percentage of (88.7%). The insecticidal property was achieved against Tychius aureolus and Hypera postica. This preliminary study showed that the essential oil of Pelargonium graveolens L. exhibits remarkable toxicity towards these insects. The results of the tests showed a very important activity during 24 hours of the treatments confirmed by the values of LD50 and LD90. This activity was probably due to the major constituents. The antimicrobial power was studied in vitro against agricultural bacteria extracted from Medicago sativa L. Respectively Agrobacterium tumefaciens, Corynebacterium insidiosum, Pseudomonas, savastanoi pv. phaseolicola and Pseudomonas viridiflava. The results of the tests made it possible to quantitatively evaluate the bacterial power by looking for minimum inhibitory concentrations of MIC and minimum bactericidal concentrations of MBC, which showed a remarkable activity and an inhibitory effect against the strains tested.