Aim: After the Great East Japan Earthquake, over 160,000 residents near the Fukushima Daiichi Nuclear Power Plant were forced to evacuate due to a nuclear accident. Health problems in these evacuees have since become major issues. We examined the association between evacuation and incidence of metabolic syndrome (METS) among residents in Fukushima.Methods: We conducted a cohort study among residents aged 40-74 years without METS at the time of the disaster in Fukushima. Among 20,269 residents who met the inclusion criteria before the disaster, 8,547 residents (3,697 men and 4,850 women; follow-up proportion: 42.2%) remained available for follow-up examinations after the disaster by the end of March 2013. The main outcome was incidence of METS, defined by guidelines from the Japanese committee, using data from the Comprehensive Health Check before and after the disaster. We divided participants by evacuation status and compared outcomes between groups. Using a logistic regression model, we estimated the odds ratio for incidence of METS, adjusting for potential confounders, age, gender, waist circumference, exercise habit, and alcohol consumption.Results: Incidence of METS was higher in evacuees (men 19.2%, women 6.6%) than in non-evacuees (men 11.0%, women 4.6%). Evacuees had higher body mass index, waist circumference, triglycerides, and fasting plasma glucose after the disaster than non-evacuees. We found a significant association between evacuation and incidence of METS (adjusted odds ratio 1.72, 95% confidence interval; 1.46-2.02).Conclusion: This is the first study to demonstrate that evacuation after a disaster is associated with increased incidence of METS.