A trial was conducted to evaluate the efficacy of essential oil supplementation on laying hen egg production and quality, and gut health. Fifty-four Lohman LSL-Classic laying hens were randomly assigned to 3 treatments and provided different levels of a liquid essential oil blend containing Citrus, Oregano, and Anis oils in drinking water from 31 to 39 weeks of age. Hens received a control treatment (no essential oils), essential oils level-1 (30 ml per 1000 ml of water), or essential oils level-2 (60 ml per 1000 ml of water). The layer diet was formulated according to the specifications listed in the nutrition guidelines of Lohman LSL-Classic and fed throughout the experimental period. Each of the 3 treatments had 6 replicates of 3 hens each. Data were analyzed as a one-way ANOVA using the GLM procedure. No significant differences were observed in egg production data between the groups. Heavier egg weights (P<0.01) were observed in the control treatment followed by level 2 and then level 1 for weeks 1 and 3. However, egg weight was heavier (P<0.0001) for levels 2 and 1 compared to the control treatment at week 4. No significant difference were observed for shell thickness. Haugh units were higher (P<0.01) for level 2 compared to control and level 1 at week 4. At the end of the study, jejunum villi length and crypt depth were higher (P<0.01) for levels 2 and 1 compared to the control treatment. There were no significant differences among ileum measurements or blood chemistry parameters at any point during the experiment.