Determining the dietary requirements of sulphur containing amino acids (SAA), particularly methionine (Met), is critical for formulating nutritionally balanced poultry diets. The objective of this study was to evaluate the effects of different dietary Met levels on growth, production and egg quality of laying hens from 65 to 72 weeks of age. A total of 480 Hy-Line Brown laying hens were randomly assigned to six dietary groups for eight weeks. The treatments consisted of diets formulated to provide 90, 95, 100, 105, 110, and 120% o of the SAA levels recommended by the National Research Council (NRC), with 100% SAA serving as the control (CON). Growth was recorded at the beginning and at weeks 2, 4, 6, and 8, while egg production and feed intake data were measured weekly. Egg quality parameters were recorded at weeks 2, 4, 6, and 8. Supplementation with 90, 95, and 120% SAA significantly reduced egg production, egg weight, and feed conversion ratio (FCR), while 105 and 110% SAA levels were comparable to the CON. Egg quality traits, including Haugh unit, eggshell strength, and eggshell thickness were unaffected by the dietary treatments. These findings demonstrate that decreasing Met to levels below NRC recommendations, or increasing it by more than 10%, negatively affects production performance. The NRC-recommended dose is therefore appropriate for Hy-Line Brown laying hens at 64 weeks of age.