The Saitama Cohort Study aimed to investigate risk factors for cancer and other diseases over time. Over 8,500 participants mostly aged older than 40 years were recruited from the town of Yoshimi in Saitama Prefecture, Japan. All participants completed a baseline questionnaire in 1986 and a subsample of 3625 participants gave blood samples at health screening check between 1986 and 1990. Participants were followed up using linked healthcare and mortality data 11 years after baseline data was collected.