Technical Abstract: Oat kernel size uniformity is important to impact dehulling settings for optimal dehulling efficiency in commercial oat milling. Here we compare hulled oat size distributions with those of naked oats. Normal hulled oats have bimodal size distributions, which appears to be related to the architecture of the oat spikelet. Most oat spikelets have two kernels, where the primary kernel is distinctly larger than the secondary kernel. Naked oats have a distinctive multiflorous spikelet architecture. Our analyses indicated that spikelets from the ten naked oat genotypes contained from one to six kernels. Single kernel and double kernel spikelets were the most abundant. Analyses of size distributions indicated that all hulled oats and most naked genotypes had size distributions departing from normality, but many naked genotypes had normal size distributions. Also, the variances of naked oat size distributions were much smaller than those of hulled genotypes, indicating a greater degree of uniformity in naked genotypes. A test for bimodality indicated that many naked genotypes were less bimodal than the hulled lines. The results suggested that the multiflorous type naked oat spikelets may generate better uniformity for kernel size that the hulled oat spikelet.