The objective of present studies deals with the Preliminary Phytochemical and antimicrobial studies oil of seed of Butea monosperma Lam. Seed oil exhibited antimicrobial activity against all five microorganisms the paper disc diffusion method was employed. From zone of inhibition oil showed prominent antibacterial activity. Seed oil of Butea monosperma Lam. was more active against B. subtilis and fungus C. albicans (zone of inhibition 13.66 ± 2.08 mm, 13.66 ± 0.5 mm respectively). Oil of seed of Butea monosperma Lam. was also active against gram positive bacteria S. aureus (zone of inhibition 11.33 ± 0.57 mm) while it is less effective against gram negative bacteria P. aeruginosa and E. coli (zone of inhibition 6.4 ± 0.30 mm, 7.3 ± 0.26 mm). It can also be seen that the MIC and MBC values of the oil on S. aureus was same that is 156.25µg/ml. The present study on preliminary phytochemical and antibacterial studies of Seed oil of Butea monosperma Lam. might be useful to supplement information in regard to its identification parameters assumed significantly in the way of acceptability of herbal drugs in present scenario lacking regulatory laws to control quality of herbal drugs.