Animal welfare is nowadays a growing concern specially in relation with the intensive animal production for food industry. The implementation of biosecurity measures can provide tools to guarantee the proper and healthy animal farming. In fact, and in accordance with the Sustainable Development Goals (SDG), the SDG 12 highlights the need for a more responsible consumption and production of food in which the animal welfare should be considered. One of the most consumed foods of animal origin is egg. The laying hens and the intensive egg production systems in place can be very severe for poultry, including restricted spaces with shared drinkers and feeders together with weak nutritional and hygiene conditions, leading to a stressful environment for the animals. In poultry, an indicator of stress is the occurrence and raising of corticosterone concentration that may be detected in animal tissues and eggs. The main goal of the present work was to develop and validate an ultra-high performance liquid chromatography method coupled with a triple quadrupole mass spectrometry detector (UHPLC-MS/MS) to detect and quantify the levels of corticosterone in eggs. Several extraction procedures were tested and the final method was fully validated for the determination of corticosterone in full eggs. Validation, and acceptance criteria evaluation, was performed in accordance with the Commission Implementing Regulation (CIR) 808/2021 in which the parameters assessed were: specificity, selectivity, linearity, precision, recovery, CCa and CCb. The method presented can contribute to monitor the quality of laying eggs production and in helping to certify the final product, the egg, since the consumers are increasingly conscious and aware of the welfare of farm animals.