These guidelines on Phenotypic characterisation of animal genetic resources address Strategic Priority Area 1 of the Global Plan of Action - ""Characterisation, inventory and monitoring of trends and associated risks"". They offer advice on how to conduct a well-targeted and cost-effective phenotypic characterisation study that contributes to the improvement of animal genetic resources management in the context of country-level implementation of the GPA. An overview of the concepts and approaches that underpin phenotypic characterization is followed by practical guidance on planning and implementing field work, data management and data analysis.