Introduction: Iatrogenic perforation of the pulp chamber floor or the root is a major endodontic complication that may cause treatment failure. Aims: The objective of this study is to analyze the frequency of iatrogenic perforations made during endodontic treatment by last year dental students. Investigating the most affected groups of teeth, and the most common localization of the perforations will help to determine which steps of the endodontic procedure need an alternative approach in students__ampersandsignrsquo; training and will ultimately improve the education process. Methodology: The data were collected from patient records and obtained from clinical exams during the academic year 2016. The final data comprised 493 teeth. All perforations were confirmed clinically and on an x-ray. Clinical criteria included sudden bleeding or pain during instrumentation; the presence of blood on paper points, confirming perforation via apex locator. Results: 20 iatrogenic perforations were identified during the endodontic treatment of 493 teeth or 4,1% of all clinical cases. More perforations were made in upper posterior teeth (premolars and molars) -45% of all the perforations. The type of the tooth was found to be of no significance for the occurrence of perforation p__ampersandsigngt; 0, 005. 11 teeth or 55% of all 20 perforations were apical, followed by perforations in the furcation area. There are no significant differences found in different types of localization of iatrogenic perforations. Conclusions: Analyzing the data from the current study allows us to establish the need to improve students__ampersandsignrsquo; practical skills in endodontic treatment of molars and to improve their training in using apex locators so there are fewer apical perforations