This research was carried out to determine the variation in spikelet groups, genotypes and environments for macronutrient (Ca, Mg and K) and micronutrient (Na, Cu, Fe, Mn and Zn) concentrations of oat (Avena sativa L.) groat. The panicles of 16 Turkish oat (Avena sativa L.) genotypes were obtained from three locations; Kahramanmaras, Konya and Cumra in Turkey in 2002-2003 cropping year. The panicles of each variety were divided into three spikelet groups as basal spikelet (BS), central spikelet (CS) and apical spikelet (AS). The oat groats belonging to spikelet groups were pooled to determine macronutrient and micronutrient concentrations. The results indicate that grain number (GNP) and grain weight per panicle (GWP) were significant for locations (L), genotypes (G) and spikelet groups (SG). Genotypes were significantly different for Ca, Mg and K concentrations. Locations had significant effect on Ca and Mg concentrations while there were not any significantly differences for spikelet groups. Locations had significantly effect on micronutrient concentrations (Na, Cu, Mn and Zn) except Fe concentration of oat groats. Genotypes were significantly different for all micronutrient concentrations, while spikelet groups were significant for only Zn concentrations. Location x genotype (L x G) interaction was significant for all micronutrient concentrations, while L x G interaction was significant for Ca and Mg concentrations in macronutrients.