Background: Antibiotic resistance is a problem leading to difficulty in treating microbial infections thatmay occur due to many causes. For the important pharmacist role as a reference for the information and theability to access to medications, they are vital members in lowering the development of antibiotic resistance,and also they support the proper use and control of antibioticsmisuse. Our goal is comparing the knowledge,attitude, practice of undergraduate and postgraduate pharmacy students and their perceptions about thecausing factors of antibiotic resistance in Iraq.Method: A cross sectional study was conducted involving the final year bachelor and postgraduate (masterand Philosophical doctor) students from different private and public pharmacy universities in Iraq. Anadjusted questionnaire was administrated to 233 students electronically and the results obtained wereanalyzed by using SPSS 20 for Windows Descriptive. A significant difference was found in the knowledgeof antibiotic between undergraduate and postgraduate(Master and Philosophical doctor) students (Meanknowledge score5.32 versus 5.92 respectively, p<0.001).Attitude data also showed a higher positive attitudeof postgraduate students according to antibiotic use and resistance when compared to undergraduatestudents (Mean attitude score: 2.97 versus 2.92 respectively, p<0.05). Significant difference was observed inpractices of the comparative students groups regarding to the frequency of self- medication, reason, sourcesof antibiotic use and in terms of disease condition where they used(p<0.05) . Continuous mutation and genechanges of micro-organism taken the higher percentages answere d yes for the undergraduate students whilethe limited restrictions on antibiotic usage taken the higher percentages answere d yes for the postgraduatestudents (89.1% and 98.5%respectively).Conclusion: We can conclude from data of our study that there is a significant difference in the knowledge,attitude, practice of antibiotic use and perceptions of the possible causes of resistance between postgraduate(master and Philosophical doctor) and undergraduate (fifth year bachelor) pharmacy students when assessingthe use of antibiotic and related resistance. This will help to determine the educational requirements forpharmacy students in colleges of Iraq for better understanding and dealing with the antibiotic resistanceproblem in the future