This study aims to examine the differences in the impact of simulation classes using stimulated recall on pre-service early childhood teachers' teaching competencies with a focus on grit. Sixty-eight third-year students majoring in early childhood education at a 3-year college in Gyeonggi Province were selected for this study. Data collected before and after the survey were analyzed using descriptive statistics, paired sample t-tests, and independent sample t-tests. The study's results are as follows: First, simulation classes with stimulated recall significantly impacted the teaching competencies of pre-service early childhood educators. Second, a statistically significant difference exists in teaching competencies of pre-service early childhood teachers between the high and low grit groups. The results suggest that stimulated recall classes effectively enhances the teaching competencies of pre-service early childhood teachers. It also emphasizes the importance of identifying teaching competency factors based on grit level and suggests the need for differentiated curriculum operation and support to improve teaching competencies during teacher training programs.