Plants are among the most important common sources of potentially valuable new drugs. Therefore, to investigate biological activity of medicinal plants are used to develop new drugs. Artemisia absinthium L. is an aromatic plant of the family Asteraceae, and is known by the common names wormwood and absinthe. The study of this research was aimed to chemical investigation, essential oil analysis and antibacterial activity of A. absinthium. The plant was collected in different local area of north Wollo, Woldiya. Maceration technique was used for extraction. Isolation of essential oil was done using Cleavinger apparatus. Column chromatography was used to isolate major compounds. In this present study, the major plant secondary metabolites present in A. absinthium was screened, the major constituents the plant was investigated and antibacterial activity of the crude extracts was performed. The results of phytochemical screening showed the presence of alkaloid, flavonoid, carbohydrate, tannin, quinines, protein, phenol and terpenoids. The identified components account for 56% of the oil. The oil contains camphor as a major constituent and account for 41% of the oil. From column chromatography two compounds, chamazulene and davanone were isolated and identified on the bases of their 1H and 13C NMR spectra. Antimicrobial assay of the crude extracts of A. absinthium against gram negative (E. coli and K. pneumonia) and gram positive (L. monocytogen and S. aureus) pathogenic microorganisms showed that a significance activity. Different concentrations of methanol and chloroform were tested and maximum zone of inhibition was found at 200mg/ml in both extracted and zone of inhibition was decreased with decreasing concentrations.