A facile and effective method to obtain urchin-like structures and ordered arrays of rod-like crystals of scandium fluoride by an interfacial interaction between solution and gaseous reagents (Gas-Solution Interface Technique, GSIT) is reported. The rod crystals with tetragonal crystal lattice can be as thin as ca. 200 nm and as long as ca. 7 μm. The effect of solution concentration and reaction time on the morphology of the product is reported. The synthesized crystals were characterized by SEM, TEM, HRTEM, XRD analyses, EDS, XPS, and FT-IR spectroscopy. A hypothesis is proposed on the formation of rod crystals during the GSIT process.