Background: Cognitive-behavioural interventions may be important for the prevention and treatment of oral diseases. One cognitive factor that has generated considerable interest as a possible mediator is self-efficacy. Methods: One hundred patients diagnosed with pulpal or periapical pathology that required endodontic therapy were treated. Data were collected at baseline in the waiting room before therapy and then during treatment. Results: Positive correlations were found between dental fear, pain anticipation and dental avoidance (p<0.001). The correlation between dental fear and pain anticipation showed the largest effect sizes. Healthy participants had higher scores in self-efficacy (Mean=32.55; SD=7.15) than those with systemic diseases (n=15; Mean=29.33; SD=4.76, p=0.04). Participants who not taking medication before treatment had lower scores for pain anticipation (Mean=3.63; SD=2.85) than those taking medication. The contribution of pain anticipation to dental avoidance varied at different values of self-efficacy. The indirect effect of dental fear on dental avoidance via dental anxiety was significant in individuals with higher self-efficacy. Conclusions: Self-efficacy had an essential moderation role between pain anticipation and dental avoidance during endodontic treatment. Keywords: Self-efficacy, endodontic therapy, dental fear, dental avoidance