In this present study minimum inhibitory concentration of Moxifloxacin hydrochloride is determined by using cup plate method. Moxifloxacin Hydrochloride belongs to fourth generation fluoroquinolone antibiotic which is effective against both gram positive and gram negative microorganisms. Since moxifloxacin hydrochloride is a broad spectrum antibiotic Staphylococcus aureus and Escherichia coli is selected as test organisms. Serial dilution of Moxifloxacin Hydrochloride were made in the concentration ranging from 5000 µg/ml to 2.43µg/ml. Minimum inhibitory concentration of Moxifloxacin Hydrochloride was found out at 312.5µg/ml when seeded with S aureus and 19.5µg/ml when seeded with E coli