The main aim of this study was to investigate the effect of six different levels (0, 50, 100, 200, 400, and 600 mg/kg) of phytogenic feed additive containing a mixture essential oils from thyme, black cumin, fennel, anise and rosemary on performance, eggshell quality, reproductive traits, and mineral excretion in quail breeders. In this trial, a total of 60 male and 120 female quails, 91 days old, were randomly distributed in six experimental groups. During the 60-day experiment period, birds were fed with six treatment diets. Performances, eggshell qualities, hatchability, and mineral excretion data were evaluated at the end of the experiment. Results showed that the different dietary levels of essential oil mixture had no significant effect on performance parameters, damaged eggs, eggshell weight, fertility, hatchability of fertile eggs, hatchability of set eggs, and lead and boron excretion. On the other hand, 50 mg/kg supplementation of essential oil mixture (EOM) significantly improved egg-breaking strength and eggshell thickness, and ash, calcium, phosphorus, magnesium, manganese, zinc, and cadmium excretion was significantly depressed in quail breeders supplemented with the two higher doses (400 or 600 mg/kg) of EOM. These results concluded that supplementing diets with EOM improved egg-breaking strength and decreased excretion of minerals in breeder quails.