Morphological and structural features of buckwheat starch granules and nanocrystals were examined using atomic force microscopy. Partially digested starch granules revealed a clear pattern of growth rings with the central core showing lamellar structure. Atomic force microscopy and dynamic light scattering experiments revealed that the buckwheat starch granules were round or polygonal in shape and were in the range of 3 to 12 µm in diameter. Aqueous suspensions of starch using acid hydrolysis produced starch nanocrystals. The starch nanocrystals were in the shape of rods with lengths ranging from 120 to 200 nm, and diameters ranging from 2 to 6 nm respectively. New understanding of buckwheat starch components morphology and the granule concentric growth rings has been achieved through our study. Biocompatibility nature of buckwheat starch nanocrystals and their structural properties makes them a promising green nanocomposite material.