This study was conducted to evaluate effects of dietary supplementation with phytogenics on production performance, feed intake, egg quality, excreta microbiota, noxious gas emission, and nutrient digestibility in laying hens. Total of 240 Hy-line Brown 50-week-old laying hens were randomly assigned to 1 of 4 treatments. The dietary treatments included (1) T1, basal diet (ingredients included Ca: 4.92%; protein: 16.9%, phosphorus: 0.64% and energy: 3920 kcal/kg); (2) T2 = T1 + 150 ppm phytogenics (quillaja 30%, anise 20% and thyme 17%); (3) T3 = T1 + 150 ppm phytogenics w/matrix (reduction in Ca −0.072% and P −0.068% only; (4) T4 = T1 + 150 ppm phytogenics w/matrix (reduction in Ca −0.072%, P −0.068%, protein −0.5%, energy −32 kcal/kg and amino acids). Variability in the data was expressed as the pooled standard error (SE) and probability level of P < 0.05 was considered to be significant. Egg weight was improved (P < 0.05) by the T2 (62.95), T3(63.54) and T4 (61.02) treatments compared with the T1 treatment during wk 15–20. The feed intake was higher (P < 0.05) in the T3 (112) and T4 (115) treatments than the T1 and T2 treatments. The yolk height in the T4 treatment (8.38) was higher (P < 0.05) than that in the T1 treatment at wk 20. T2 (8.95) and the T4 (9.00) treatments had higher (P < 0.05) yolk color compared with that in the T3 treatment at wk 15. E. coli and lactobacillus counts were not affected by dietary treatments. Laying hens in T3 (14.2) and T4 (16.4) treatments excreted significantly less (P < 0.05) ammonia than that in the T1 and T2 treatments at wk 20. At wk 15, the T1 (59.25) treatment had the greater (P < 0.05) ATTD (apparent total-tract digestibility) of Ca compared with the T3 treatment. Meanwhile, the T2 (47.59) and T4 (48.53) treatments had greater (P < 0.05) ATTD of P compared with the T1 and T3 treatments. At wk 20, the T3 (48.90) group had the highest (P < 0.05) ATTD of P when compared with the T2 and T4 groups. Thus the dietary supplementation with phytogenics has some influence on performance, feed intake, egg quality, excreta microbiota, noxious gas emission, and nutrient digestibility in laying hens.