Background: Antibiotics serve as wonder drug to combat against harmful microorganisms. Inappropriate and rampant antibiotics use is a major contributing factor for antibiotic resistance in the community. Insufficient knowledge about antibiotics usage and wrong prescribing pattern among the prescribers add to the magnitude of antibiotic resistance. Assessing the knowledge, attitude, and practices (KAP) of the future prescribers with regard to rational antibiotic use can help in planning and formulating suitable educational strategies for them during the course of study itself. Aims and Objectives: The primary objective of the present study was to evaluate the KAP of rational antibiotic usage among 3rd-year medical students in a tertiary care teaching hospital of Assam, India. Materials and Methods: A pre-validated and structured questionnaire was utilized to gather data on demographic profile and KAP of medical students pertaining to antibiotic usage. Data collected were subjected to descriptive analysis. Results were expressed as percentage under each response category. Results: A greater lot of the respondents (95.87%) had adequate knowledge about antibiotic use. The notion of antibiotic resistance was heard of but not clearly understood. The attitude results revealed that 79.34% of the respondents took antibiotics for common cold while 21.64% of respondents stopped taking antibiotic when they started feeling well. Approximately (25.77%) of participants admitted to have procured antibiotics without a valid prescription. Conclusion: The study provides baseline evidence and paucity in KAP regarding use of antibiotic among medical students in a tertiary care teaching hospital of Assam, India. Suitable educational interventions are a requisite to reinforce existent courses and instruction about rational use of antimicrobials with greater emphasis on antimicrobial stewardship.