The aim of this study was to relate morphometric measurements of the Coturnix coturnix japonica quail egg with the weight at birth in a commercial line of laying. In total, 274 birds were evaluated at one-day old, whose fertile eggs were classified into three categories according to weight: (1) 10.00-10.99, (2) 11.00-11.99, (3) 12.00-12.99 g for the variable birth weight, while the variables: transverse diameter and longitudinal diameter of the egg, and shape index were evaluated according to quartiles. In addition, the sex of the bird was evaluated. A completely randomized block model and correlations between the quantitative variables were used. A mean correlation of 0.65 was obtained between egg weight and longitudinal diameter, and low correlations between the variables longitudinal and transverse diameter (0.15). The birth weight was 7.36 ± 0.038, 7.92 ± 0.036 and 8.47 ± 0.058 g ...