Neodymium hexaboride (NdB₆) submicroawls have been fabricated via a simple flux-controlled self-catalyzed method using neodymium (Nd) powders and boron trichloride (BCl₃) as starting materials at 1000 °C. Scanning electron microscopy (SEM) reveals that the submicroawls are tapered, with a length of 2–5 μm and a diameter ranging from approximately 0.1–0.3 μm at the roots and 5–50 nm at the tips. Transmission electron microscopy (TEM) shows that the submicroawls are single crystalline with the preferred growth direction along [001]. For systematic research, we have discussed the morphological change of NdB₆ submicron structures by varying reaction temperatures, catalysts and duration. Moreover, a multistage growth model of the NdB₆ submicroawls is proposed.