The Yorkshire Health Study is a longitudinal observational regional health study collecting health information on the residents from the Yorkshire and Humberside region in England. The second wave of data collection is currently under way. The study aims to inform National Health Service (NHS) and local authority health-related decision making in Yorkshire, with wider implications from findings as well. The first wave contains records for 27 806 individuals (2010–12), aged between 16 and 85, from one part of Yorkshire (South Yorkshire), with the second wave expanding data collection to the whole of the Yorkshire and Humberside region. Data were collected on current and long-standing health, health care usage and health-related behaviours, with a particular focus on weight and weight management. The majority of individuals have also given consent for record linkage with routine clinical data, allowing the linking to disease diagnosis, medication use and health care usage. The study encourages researchers to utilize the sample through the embedding of randomized controlled trials, other controlled trials and qualitative studies. To access the anonymized data or use the sample to recruit participants to studies, researchers should contact Clare Relton ( c.relton@sheffield.ac.uk ).