Background Betaglycan, also known as the TGFβ type III receptor (Tgfbr3), is a co‐receptor that modulates TGFβ family signaling. Tgfbr3 is upregulated during C2C12 myoblast differentiation and expressed in mouse embryos myocytes. Results To investigate tgfbr3 transcriptional regulation during zebrafish embryonic myogenesis, we cloned a 3.2 kb promoter fragment that drives reporter transcription during C2C12 myoblasts differentiation and in the Tg(tgfbr3:mCherry) transgenic zebrafish. We detect tgfbr3 protein and mCherry expression in the adaxial cells concomitantly with the onset of their radial migration to become slow‐twitch muscle fibers in the Tg(tgfbr3:mCherry). Remarkably, this expression displays a measurable antero‐posterior somitic gradient expression. Conclusions tgfbr3 is transcriptionally regulated during somitic muscle development in zebrafish with an antero‐posterior gradient expression that preferentially marks the adaxial cells and their descendants. Key Findings Tgfbr3 is transcriptionally regulated in zebrafish muscle. Tgfbr3 is specifically expressed in adaxial cells and slow twitch somitic muscle. Tgfbr3 is expressed in an antero‐posterior somitic gradient.