This study was carried out to the effects of supplementation of phytase enzyme to free-range layer diets on performance and egg quality traits. In the trial, at 48 wk old 152 Lohman Brown layers were divided into 3 dietary treatments with 2 replicates. Diets were fed 8 wk periods. Basal diets with 16, 75% crude protein and 2795 kcal/kg metabolisable energy were used. Three dietary treatments were formed as followed; (1) control group diet had 0 FTU/kg with phytase (T1), (2) T2 group diet had 250 FTU/kg phytase and (3) T3 group diet had 500 FTU/kg phytase. Feed and water were supplied for ad-libitum. Light was provided 16 hours daily. The results were indicated that egg production, feed intake and egg weight were significantly (P<0,01) increased by phytase addition. The treatments did not affect egg shape index, haugh unit and specific gravity. On the other hands, phytase supplementation was increased egg weight, albumen and yolk weight, egg shell weight and shell thickness. An according to result of the experiment that phytase supplementation of free-range layer diets had significant positive effects on performance and egg quality traits.