Selinum wallichianum is a perennial herb, grows in temperate Himalayan forests is traditionally used as incense and therapeutics in common ailments like, cough, cold, fever, wounds, stomachache and toothache etc. The present study was designed to evaluate the antimicrobial activity and minimum inhibitory concentration (MIC) of Selinum wallichianum essential oil (SWEO) extracted from leaves and tender stem branches on two reference strains of E. coli, (E3376 and E3382) and 94 bacterial strains of 10 genera isolated from clinical cases, environment and food items. Both the reference strains were sensitive to the oil while among the test strains, none of the Bacillus coaggulans strains, one isolate each of E. coli, Aeromonas hydrophila and Lactobacillus acidophilus, three strains of Klebsiella pneumoniae and majority of Enterococcus strains were resistant to SWEO. The MIC of sensitive and resistant strains was ≤32 µg/ml and >32 µg/ml, respectively. The findings justified the eth- nomedical use of S. wallichianum extract to cure pyrexia, gastrointestinal infection, wound infection and food popisoning etc. Although antibacterial activity has been reported in ethanolic extract of roots of S. wallichianum earlier, it appears to be the first report of the potent antimicrobial activity in essential oil of aerial parts of S. wallichianum.