This study aims to examine the effect of AI-assisted multimodal storytelling on elementary school students’ narrative writing skills. The study employed a quantitative approach with a quasi-experimental design involving an experimental group and a control group. The participants were 60 elementary school students, comprising 30 students from SD Negeri 45 Banda Aceh in the experimental group and 30 students from SD Negeri 16 Banda Aceh in the control group. Data were collected through narrative writing tests administered before and after the intervention. The data were analyzed using descriptive statistics, including mean scores, standard deviations, and learning mastery percentages, as well as inferential statistics using independent-samples and paired-samples t-tests. The findings showed that students who received AI-assisted multimodal storytelling instruction achieved substantially higher narrative writing performance than those who received conventional instruction. The experimental group obtained a mean posttest score of 89.81, compared with 61.53 in the control group. The experimental group also demonstrated a lower standard deviation, indicating a more consistent distribution of students’ writing performance, and achieved a higher learning mastery percentage of 91.76%, compared with 68.29% in the control group. The prerequisite analyses indicated that the data were normally distributed and that the group variances were homogeneous. Furthermore, the independent-samples and paired-samples t-tests yielded a significance value of 0.000, indicating statistically significant differences and improvements in narrative writing performance. These findings suggest that AI-assisted multimodal storytelling can serve as a promising instructional approach for supporting elementary school students’ narrative writing development by providing opportunities for idea generation, multimodal representation, and active engagement in the writing process.