Drug-Drug Interactions are the interactions between two or more drugs it may be a pharmacological or a clinical response. There are many of drug-drug interactions found now-a-days in many prescriptions. These are to be minimized so as to prevent from adverse effects, further complications which sometimes lead to serious ill effects or sometimes even lead to death. The observational study was performed in a tertiary care multi specialty hospital to assess drug - drug interactions which are classified into major, moderate and minor. Major and moderate interactions were observed in some of the prescriptions. These types of interactions mainly lead to serious complications whereas minor interactions can be neglected as they do not cause any serious ill effects. The prescriptions of few patients were reviewed daily and assessed for drug - drug interactions in various departments of the hospital and assessed age wise, gender wise, and department wise. According to age groups, elder aged people prescriptions were found with more drug-drug interactions than middle aged people prescriptions. According to gender wise, male patient prescriptions had more interactions when compared to female patient prescriptions. According to department wise, Cardiology, General department, Nephrology cases had more drug-drug interactions than when compared to other departments. The study concludes that, the better patient care can be obtained by regular reviewing of the prescriptions.