This study evaluated the technical quality (TQ) of root canal therapy (RCT) performed by predoctoral students and its impact on endodontic outcome (EO) and patients' quality of life (QoL). The TQ of RCT done by predoctoral students was evaluated and follow-up visits were conducted to determine the clinical, radiographic outcome of RCT and patients' QoL. Frequency distribution, multiple regression, independent-samples t test and one-way anova were performed. A total of 226 teeth of 164 patients were clinically and radiographically examined. A satisfactory TQ was observed in 130 (57.5%), successful clinical outcomes in 155 (68.6%), successful radiographical outcomes in 206 (91%) and overall successful EO in 150 teeth (66.4%) with 80% of patients reporting a favourable QoL. A significant positive correlation was noted between EO and QoL (p = 0.002) with no significant correlation in between TQ-RCT and EO (p = 0.07) and TQ-RCT and QoL (p = 0.316). Successful EO had a positive impact on patients' QoL.