Drawing on Vygotsky’s Socio-cultural Theory, this study directly compared the writing outcomes of emergent second language (L2) writers who adopted a drawing-led approach to a guided writing approach. While past research has investigated how drawing served as a mediator to facilitate social speech for better writing performance, little is known about the sheer effect of drawing on second language writing without oral language effect from socialization, via the channel of inner speech. This study involved a total of 90 kindergarten children (mean age 6 years 1 month, SD 3 months) from 5 kindergartens in Hong Kong. Through an English writing enhancement program, this study compared the writing outcomes of emergent L2 writers under two seemingly incompatible approaches using mixed methods approach. The results revealed that the drawing-led group significantly outperformed the guided writing group in text length; and drawing-led group with high English language proficiency level significantly outperformed the guided writing group in text complexity. Qualitative analysis also suggested children in the drawing-led group demonstrated higher level of flexibility in syntactic, semantic, and pragmatic language use, contributing to more elaborated pieces of writing. When instructional writing approaches have recently gained more interest under the current educational climate, these findings extend our knowledge on how drawing functions as a mental tool to facilitate intra-psychological stage of learning for better writing performance.