The LIFEWORK cohort is a large federated prospective cohort including over 88,000 participants across three separate cohorts in the Netherlands. Firstly, over 13,000 adult participants were included from the existing European Prospective Investigation into Cancer and Nutrition in the Netherlands (EPIC-NL), who were originally recruited between 1993 and 1997 via a breast cancer screening program in Utrecht and neighbouring towns, or from the general populations of Amsterdam, Doetinchem, and Maastricht. Secondly, over 59,000 current and former female nurses were included from the newly established Nightingale Study, recruited in 2011 via the registration system for healthcare professionals. Thirdly, over 14,000 adult participants were included from the newly established Occupational and Environmental Health Cohort Study (AMIGO), recruited between 2011 and 2012 via a national general practitioners network, the NIVEL Primary Care Database. The resulting LIFEWORK cohort consisted of 90% female participants, with 66% being nurses, and a median age of 51 years across all participants.