Antibiotic resistance is now a major a medical and financial burden that affects healthcare globally. Insufficient undergraduate instruction on antibiotic management may be a factor in antibiotic-related clinical malpractice, which could have detrimental effects on patient wellness. The study's objective was to evaluate undergraduate medical students at the Medical Institute in Al-Nasiriyah understanding, beliefs, and behaviors regarding resistant antibiotics. Methodology: A cross-sectional investigation was making in the University of the Medical Institute in Al-Nasiriyah. (133) undergraduate medical students who were chosen at random were given a structured questionnaire. The statistical package for social sciences and SPSS, version 22.0, was used to analyze the data. A Chi-square test was used to examine relationships between the independent and dependent variables. Results: 133 of 188 medical students (71%) had good understanding about the use and resistance to antibiotics, according to the study. Regarding antibiotics and antibiotic resistance, the students' knowledge is good; however, their understanding of antibiotic usage is below average. Knowledge is influenced by a number of variables, such as program, academic level, gender, and awareness of resistance to antibiotics. Based on the results, it is recommended that students' understanding of these topics be enhanced. Conclusions: There are a lot of common misconceptions in some fields, like the usage of antibiotics. Immediately interventions are necessary to enhance students' understanding of antibiotics and resistance in light of the findings. Although they were less practiced, the students' knowledge and attitudes were higher.