The protein and oil quantities of walnut samples were established to be between 19,055 ‘Kaman 1’ and 22.90% ‘Göçmen’ to 61.00 ‘Göçmen’ and 64.75% ‘Kaman 1,’ respectively. The P and K amounts of walnut varieties were determined between 2423.3 ‘Kaman 5’ and 3067.1 ppm ‘Fernor’ to 2826.2 ‘Kaman 1’ and 3378 ppm ‘Kaman 5,’ respectively. The highest P, K, Ca, and Mg were recorded in ‘Fernor,’ ‘Chandler,’ ‘Kaman 1,’ and ‘Göçmen’ walnut varieties, respectively. Total phenolic and flavonoid amounts of walnut fruits were recorded to be between 82.30 ‘Chandler’ and 116.04 mgGAE/100 g ‘Kaman 5’ to 117.43 ‘Chandler’ and 234.43 mgCE/100 g ‘Kaman 5,’ respectively. Tannin contents of walnut samples varied between 126.12 ‘Chandler’ and 300.92 mg/kg ‘Kaman 5.’ Total flavonoid contents of walnut oils varied between 1.79 ‘Göçmen’ and 75.90 mgCE/100 g ‘Fernor.’ The catechin contents of walnut fruits and oils varied between 9.11 ‘Chandler’ and 91.73 mg/100 g ‘Kaman 5’ to 0.41 ‘Kaman 1’ to 8.96 mg/100 g ‘Fernor,’ respectively. In addition, the highest gallic acid, 3.4-dihydroxybenzoic acid, catechin, rutin, and p-coumaric acid were assigned to ‘Fernor’ walnut oil. Oleic and linoleic acid contents of walnut oils were recorded to be between 14.25 ‘Fernor’ and 20.48% ‘Kaman 5’ to 54.87 ‘Kaman 5’ and 63.21% ‘Fernor,’ respectively. It was observed that walnut varieties are rich in linoleic acid, and the highest linoleic acid was detected in ‘Fernor’ walnut oil. It was revealed that the most important walnut fruits in terms of composition are the ‘Fernor’ and ‘Kaman 5’ varieties.