Several requirements before and during the artificial incubation process interfere with the success of the day-old chicks production, and the quality of the eggs to be incubated is an important factor to be considered. The aim of this study was to investigate the characteristics of young and old broiler breeder eggs. We studied 200 incubating eggs produced by Cobb broiler breeders aged 29 wk (n = 100) and 62 wk (n = 100). It was used a completely randomized design. The treatments were the age and each egg was considered replication. The eggs were weighed (EW), and also its components: eggshell (ES%), yolk (Y%) and albumen (A%). Specific weight analysis (SW) was determined by the solutions of different densities method. The eggshell resistence (ER) was analyzed by compression strength test. The means of eggshell thickness (ET) and number of pores (PO) were obtained in 3 different regions. Additionally we evaluated albumen pH (pHA), yolk pH (pHY), albumen height (AH), yolk height (YH) and Haugh Units (HU). Data were analyzed using PROC GLM of SAS 9.2 and the means were compared by F test. EW, Y%, pHA were higher (P < 0.05) from the old flock as compared with the young flock (72.48 vs 57.91 g; 31.19 vs 26.30%; 8.84 vs 8.64; respectively). ES%, A%, SW, ER, ET, PO, AH, HU were higher (P < 0.05) from the young flock as compared with the old flock (8.99 vs 8.71%; 64.70 vs 60.10%; 1.082 vs 1.076 g/mL H₂O; 2320 vs 2158 g; 0,438 vs 0,428 mm; 122 vs 105 pores/cm²; 8,12 vs 7,19 mm; 82,22 vs 71,61 HU; respectively). There was no effect between the treatments for pHY and YH. The hatching eggs quality from 62-wk-old broiler breeder is less than that of 29-wk-old broiler breeder. Due to the influence of the structural characteristics of eggs in embryo development, it is necessary to monitor the quality parameters and performing further studies that aim adapt the conditions of the incubation process according to the egg to be incubated.