The aim of this study was to evaluate the feasibility and efectiveness of a mobile application as a supplementary tool in the radiographic diagnosis of endodontic complications by dental students. Radiographic images of the following endodontic conditions were selected: 1) absence of endodontic treatment (ET) without periapical lesion (PL); 2) absence of ET with PL; 3) satisfactory ET without PL; 4) satisfactory ET with PL; 5) unsatisfactory ET without PL; 6) unsatisfactory ET with PL; 7) fractured instrument; 8) deviated cast post; 9) root fracture; and 10) root resorption. In 2018, images were evaluated by 20 students at a dental school in Brazil who had been divided into experimental and control groups. The experimental group was permitted to use the Kahoot! mobile application (app) to access reference images of endodontic conditions. Reference standards were established through consensus by two endodontists and three oral radiologists. The results showed that intraobserver agreement ranged from moderate to substantial for both groups. Signiicant diferences from the specialists' reference standards were found in the evaluation of conditions 4 and 10 for the experimental group, which used the app (p<0.001), and conditions 1, 4, 6, 7, 8, and 10 for the control group, which did not use the app (p<0.05). No statistically signiicant diferences were found in accuracy, sensitivity, or speciicity values between the groups for any of the endodontic conditions evaluated (p>0.05). This study found that the use of a mobile app containing reference images improved the students' ability to diagnose endodontic complications, suggesting it would be a valuable supplementary tool in dental education.