This study aimed to estimate genetic parameters for fertility traits in Friesian heifers and traits associated with their first lactation. Data from animals that calved between 1979 and 2013 at Saka and El-Karada stations were analyzed using a multi-trait linear animal model.The heritabilities (h²) of fertility traits in both heifers and cows were generally low. For virgin heifers, the heritabilities of age-related traits (AFB, ASB, and AFC) were slightly higher (0.152, 0.161, and 0.163, respectively) compared to other fertility traits such as NSC0, CR0, and SP0 (0.027, 0.019, and 0.022, respectively). In cows, heritability estimates for NSC1 and SP1 (0.044 and 0.035, respectively) were higher than those for heifers. Genetic correlations among traits were notably high, including correlations between NSC0 and CR0 (-0.903) and SP0 (0.951), and between AFB, ASB, and AFC (0.994–0.997) in heifers. Similarly, strong correlations were observed among cow traits, such as NSC1 with SP1 (0.925) and DO1 (0.980), CR1 with SP1 (-0.994) and DO1 (-0.918), and SP1 with DO1 (0.976). These results suggest that fertility traits in both heifers and cows can be included in genetic selection. Notably, selecting heifers based on age-related traits (AFB, ASB, and AFC) may encourage earlier maturation in cows.