This study was aimed to determine the prescribing pattern and drug interaction of an antibiotic at a private hospital using WHO recommended indicators. A cross-sectional study was conducted for six months to evaluate drug utilization pattern and drug interaction of an antibiotic prescribed at an orthopedic unit at a private hospital. The drug utilization and drug interactions were studied on a total of 200 prescriptions. The average number of prescribed drugs was found 5.15 per prescription. The maximum number of patients were treated with a single antibiotic. In this study, we observed that most of the patients were at the age range of 61-70 years. In our study, 22% of drugs were prescribed by generic names and 78% were the drugs prescribed by their brand names. The most frequently prescribed antibiotic group was beta-lactam drug. The most common situation was accident in which antibiotics were prescribed in a higher ratio. No serious drug interaction was found. Mostly all the possible drug interactions occur through the pharmacokinetic mechanism. The number of medicines per prescription should be kept in minimum with an eye on therapeutic effect. In other words, rational drug must be strictly followed. Polypharmacy and combination of drugs have to be discouraged to minimize drug interactions.