This study was conducted to compare two different Japanese quail (Coturnix coturnix japonica) breed lines in terms of egg quality, egg yolk lipid peroxidation, and fatty acid profiles. The research was carried out with Jumbo Brown (Jumbo Brown Coturnix japonica) and Golden Italian (Golden Italian Coturnix japonica) Japanese quail breed lines with dark brown and golden yellow plumage colors at an average body weight of 200±10 g and 10 weeks of age. The experimental groups consisted of Jumbo Brown Japanese quail breed and Golden Italian Japanese quail breed, each containing 80 Japanese quails fed a standard quail diet. Each group was divided into 20 subgroups, with 4 quails housed in each subgroup. The study lasted for 10 weeks (11–20 weeks) according to the randomized plot experimental design. The egg quality data were recorded over an overall period, divided into two periods of 5 weeks each: period 1 (11 to 15 weeks) and period 2 (16 to 20 weeks). Egg and eggshell weights of the Golden Italian breeds were higher in the overall period (P