Background: There are two aspect of quality in drug information service, one is the quality of information available, and another is the quality method of getting, processing, and delivering it. In this article we study about the quality of drug information available for the queries requested by different health care professionals. Methods: The study was performed on a drug information service in a rural Indian hospital in 2011 and 2012. The U.S. Preventive Services Task Force (USPSTF) grading system was used for grading the quality of evidences for clinical uses of drugs. Results: Total number of queries answered in 2011 and 2012 was 726. Majority of the queries were from nurses 448, followed by doctors 140, and pharmacists 77. Other queries came from nutritionist (35), student nurses (19), and laboratory technicians (07). Ninety six percentage of information requested by nurses were available with good quality evidences. Evidences on available information requested by doctors were mostly 46% fair or poor 34% and of pharmacists was 51 % fair. Conclusion: Nurses do request information in the late stages of clinical decision making and the doctors or pharmacists were requesting information in the early stages of clinical decision making to a drug information service. Doctors mostly asked difficult queries to answer than other professionals.