Background: Success of endodontic treatment depends on different factors, and the probability of failures varies significantly in different cases. The present study was conducted to assess awareness about endodontic failures among dental students. Materials & Methods: The present study was conducted on 280 dental interns of both genders. A questionnaire was prepared and distributed among dental interns and were asked to fill it and return. It was knowledge- based, attitude-based and practice-based questions. Results: Out of 180 subjects, males were 70 and females were 110. In response to causes of root perforations, 45% responded acute angle of canal, 25% responded vigorous instrumentation, 15% responded poor file condition and 15% replied canal blockage. 50% replied that right method to treat endodontic failure in non surgical root canal treatment, 40% replied surgery and 10% replied extraction. In response to from which segment file is not retrievable easily response was apical in 40%, middle in 35% and coronal in 20%. In response to the main reason leading to failure, clinical diagnosis was given by 25%, radiographic diagnosis by 15%, anatomy of the tooth in 35% and debridement of root canal space in 25%. Conclusion: Authors found that dental students had sufficient knowledge about cause of endodontic failures. Key words: Knowledge, endodontic treatment, Questionnaire