Background <p>Preoperative state anxiety is known to influence student performance across diverse dental educational contexts. Yet, its specific impact on root canal treatment outcomes in simulation-based environments remains insufficiently explored. This study investigated the association between preoperative anxiety and students’ technical performance and subjective outcomes during their first root canal treatment on extracted molars.</p> Methods <p>Ninety-three dental students performed root canal treatments on extracted permanent mandibular and maxillary molars. Prior to each procedure, students completed the State-Trait Anxiety Inventory-State (STAI-S) to assess preoperative state anxiety levels. Scores were recorded before the procedure and grouped during the analysis as low (&lt; 44) or high (≥ 45) anxiety. Preclinical performance was evaluated based on total procedure score (access, shaping, obturation, apical accuracy, and cleanliness), treatment duration, distance to the apex, and occurrence of procedural errors. Post-procedure measures included STAI-S, perceived procedural difficulty, self-confidence, and self-reported comprehension. Statistical comparisons were conducted using appropriate parametric or nonparametric tests (t-test, Mann-Whitney U, Wilcoxon signed-rank, chi-square/Fisher’s exact), correlations were examined with Spearman’s rank test, and inter-rater reliability was assessed with Cohen’s Kappa (α = 0.05).</p> Results <p>No statistically significant differences were observed between low- and high-anxiety groups in total root canal treatment performance scores for either mandibular or maxillary molars (<i>p</i> &gt; 0.05). Treatment duration also showed no meaningful variation between groups (<i>p</i> &gt; 0.05). However, during mandibular procedures, the incidence of over-instrumentation was higher in the low-anxiety group (<i>p</i> = 0.040), whereas a non-significant trend toward increased instrument separation was noted in the high-anxiety group (<i>p</i> = 0.060). High-anxiety groups showed a significant post-procedure decline in anxiety, though scores stayed above the clinical threshold. For subjective outcomes, high-anxiety students reported lower self-confidence during mandibular procedures and lower comprehension ratings during maxillary procedures (<i>p</i> &lt; 0.05). Correlation analyses further indicated that higher anxiety was weakly associated with lower self-confidence in mandibular procedures, and with reduced comprehension and greater perceived obturation difficulty in maxillary procedures.</p> Conclusion <p>Preoperative state anxiety did not compromise technical performance outcomes, though limited associations were noted in subjective measures. Anxiety at the preclinical stage may influence perceptions more than procedural skills.</p>