Garlic (Allium sativum L.) is a plant species of cultural, medicinal importance, and is consumed globally as a very nutritious and healthy food ingredient. This study compared micro- and macro-element content, phenolic compounds, and protein content in several local garlic genotypes from varied regions of Turkey, those from China, and from Iran. Mineral contents were analyzed including macro and micro elements, total phenolics, and proteins. In this regard, the genotype 2 contributed significantly to the total phenolic content, having a value of 7359.05 mg kg^-1. Similarly, for genotype 5, a high total phenolic content of 3685.44 mg kg^-1 was recorded; it has also got high protein, 4.20%, and is rich in potassium (K), 6078.09, and calcium (Ca), 1912.74 mg kg^-1. Both hierarchical clustering analysis (HCA) and principal component analysis (PCA) displayed clear groupings in genotypes with respect to biochemical and mineral compositions. The high amounts of nitrogen (N) and manganese (Mn) constituents in genotype 1 and balanced levels in phenolic and protein content in genotype 3 also showed promising nutritional value. Genotype 4 with lesser Ca and iron (Fe) concentration had a moderate level of phenolics and protein. This work underlines the importance of genetic diversity for nutritional and bioactive compounds in garlic. These findings may be useful regarding farming technique improvements, aiming at the selection of high-quality genotypes to improve its value through breeding. These results must be confirmed by further studies in which more genotypes are tested and in various environmental conditions. Such a critical evaluation underlines the importance of genetic resources conservation as well as farming techniques improvement to obtain high nutritional quality and yield.