Walnut (Juglans regia L.) is a plant that has significant economical value and medicinal importance for human health. It is consumed in large quantities by people, therefore, it has a very important place in the public nutritive habits. Turkey has a very good walnut population of walnut varieties when compared to other parts of the world. Our objective was to investigate kernel properties and fatty acid composition, proximate composition and minerals of genotypes that are commonly grown in Turkey. Investigated genotypes were Sebin-Type-I, Körcegöz, Karabodur, Tozam and Güvenli. Physical properties are attributed to quality criteria of nuts. Sebin Type-I and Güvenli showed a good quality according to the test results. Average fatty acid compositions of genotypes (%) were 16:0; 6.88, 18:0; 7.50, 18:1; 21.16, 18.2; 43.41, 18:3; 6.25: 20:0; 11.75 for Sebin-Type-I, Körcegöz, Karabodur, Tozani and Güvenli, respectively. Proximate compounds (%) were: protein, 13.77; ash, 1.81; moisture, 2.98; fat, 62.84; total carbohydrate, 18.67. Average mineral contents (mg/100 g) were: P, 316.0; K, 270.0; Ca, 85.0; Mg, 90.0; Zn, 2.01; Mn, 2.46; Cu, 1.01; Fe, 2.90; B, 1.03.