Purpose: To determine changes in the oral-health related quality of life (OHRQoL) of preschool-aged children with severe early childhood caries (S-ECC) following dental surgery under general anesthesia (GA). Methods: Parents/caregivers completed a questionnaire including the Early Childhood Oral Health Impact Scale (ECOHIS). Data analysis included descriptive statistics, bivariate analyses, effect size, and multiple linear regression. A p value ≤ 0.05 was significant. Results: Overall, 150 children were enrolled; mean age 47.7±14.2 months and 52% female. Mean total ECOHIS score was 6.3±5.3. Higher scores (more negative OHRQoL) were associated with single parent and low income households (<$28,000/year), higher dmft scores, and having dental extractions (p≤0.05). Low household income (p=0.01) and the child not having registered First Nation status (p=0.03) were significantly and independently associated with higher total baseline ECOHIS scores. The 103 follow-up children had a mean baseline total ECOHIS score of 6.27 ±5.4 and follow-up of 3.48 ±2.9. Change in total ECOHIS and three of four Child Impact Section domains (symptoms, function, and psychological) showed significant improvement (p<0.001). Symptoms and psychological domains demonstrated a moderate effect size; 0.66 and 0.56 respectively. No significant improvements were observed in the Family Impact Section; effect size (0.03). Follow-up ECOHIS scores were associated with low income households (<$28,000/year) (p=0.01) and not having registered First Nation status (p=0.03). Conclusion: Significant improvements in OHRQoL were observed following dental surgery. ECOHIS could be used as a tool to help prioritize children waiting for dental surgery under GA.