The objective of this study was to investigate the impact of the egg shape index on egg quality characteristics. The eggs used in this study were laid by layers of the ATAK-S strain. The eggs were classified with respect to shape index (SI), namely sharp eggs (SI < 72), normal (standard) eggs (SI = 72-76) and round eggs (SI > 76). A total of 166 eggs were analysed to determine egg quality characteristics. Effects of egg shape on L*, a*, b*, specific gravity, albumen index and Haugh unit were statistically significant. However, the effects of egg shape index on egg weight,.E value, breaking strength, shell thickness, shell weight, surface area, yolk index, yolk colour, albumen pH and albumen and yolk blood spots were not significant. Statistically significant correlations between egg shape index and egg weight, L*, b*, specific gravity, egg surface area, albumen index and Haugh unit were determined. But, shape index did not correlate with a*, Delta E value, breaking strength, shell thickness, shell weight, yolk index, yolk colour and albumen pH. In conclusion, it is clear that the shape index has an effect on some egg quality characteristics. Therefore, shape index should be considered for use in future breeding programs.