The main aim of the study was to identify the physical and chemical incompatibilities among the drugs administered intravenously to patients admitted to the Intensive Care Unit (ICU) of a 1000 bedded hospital. The study also envisaged establishing pharmaceutical guidelines for the administration of incompatible medications. Methods: This prospective cross-sectional study was conducted from January to July 2018 in the ICU after getting approval from the Hospital Ethics Committee. A total of 104 medication charts were collected, and their data were analyzed. Compatibility of the selected drug with a second drug, when given together, was then analyzed using the Micromedex health-care series, Trissel's handbook of injectable drugs, and Manufacturer's product information. The pharmaceutical intervention was performed by preparing. The drug compatibility chart of selected drugs and the same was reported to the study department. Findings: Of 104 medication charts reviewed, 66 charts had incompatibility, accounting for 90 incompatibilities. Incompatibility between two intravenous (IV) bolus drugs constituted 68.8% with pantoprazole and ondansetron (85.4%) being the most frequent combination. Incompatibility between infusion-bolus was found to be 26.6%. Meropenem (infusion) and pantoprazole (bolus) constituted 16.6%. Incompatibility between two infusions in the same IV line was found to be 4.4%. A drug compatibility chart containing 19 selected drugs was prepared and submitted to the study department for their perusal. Conclusion: The current study showed that a significant number of drug incompatibilities occur in hospitalized critically ill patients in our tertiary care hospital. These incompatibilities could generally be prevented by adhering to proper medication administration techniques like flushing the line using compatible fluid or through a multi-lumen catheter or multiple IV access.