Abstract: This study was conducted to evaluate the effect of various commercial feed additives on performance and egg quality of laying hens. These additives included probiotics (Protexin® and Clostat®), symbiotic (Diamond®) and organic acids (Galliacid®). A number of 180 HL Brown hens (27 wks of age) were divided into 5 treatment groups (6 replicates of 6 birds, each). Groups were assigned to 5 experimental diets: a basal diet of no additive (control), the basal diet supplemented with either 0.01% Protexin®, 0.05% Clostat®, 0.06% Diamond® or 0.06% Galliacid®. Data of layer performance and egg quality were obtained during 12 weeks experimental period. Supplementation of probiotics or symbiotic recorded higher (p>0.05) egg production than the control but organic acids supplementation significantly (p<0.05) increased egg production by 9.94%. Egg weight slightly improved (p>0.05) by dietary treatments. Supplementation of probiotics, symbiotic and organic acids significantly (p<0.01) increased egg mass. The best egg mass value was recorded for birds fed diet supplemented with organic acids. Feed conversion ratio improved (p>0.05) by dietary treatments. Adding probiotics, symbiotic or organic acids did not significantly affect shape index, yolk index, yolk %, SWUSA, Haugh unit or specific gravity. Addition of probiotics or organic acids showed significant (p<0.05) increase in shell thickness and yolk color. It could be concluded that these additives caused improvement in performance and egg quality of laying hen. More studies are needed to explain the effects of different sources and levels of these additives on performance and egg quality of laying hens.