Egg production in line with organic principles includes outdoor access, preferential use of preventative measures and alternative treatment methods, a 100% organic diet from 2012 onwards and consistent use of non beak-trimmed birds. This proposal focuses on the main challenges for organic laying hen farms regarding disease management, adverse animal welfare and negative impacts on the environment. Parasite infestation levels as well as prevalence of major health and welfare problems such as feather pecking, cannibalism, keel bone and foot lesions are affected by a combination of housing and management factors, e.g. with respect to feeding or hygiene, genotype or therapeutic treatments. The design and management of the range influence how well and evenly it is used by the hens and the extent to which nutrients accumulate in the surrounding environment. By adopting an epidemiological approach, major risk factors for diseases, and negative welfare and environmental impacts will be identified. 107 flocks distributed over 8 countries will be included in the observational study with a cross sectional design. Flocks will be visited twice at specified age periods during two seasons. Housing, management and animal based data will be recorded during interviews, direct measurements or from farm documentation. Recommendations will be formulated based on analyses carried out in four specific work packages. These recommendations will help organic egg producers to further develop bird health and welfare according to the organic principles, and to enhance economic competitiveness through improved bird health and performance.