Background: Prospective studies mostly with European and North-American populations have shown inconsistent results regarding the association of overweight/obesity and mortality in older adults. Our aim was to investigate the relationship between overweight/obesity and mortality in an elderly Brazilian population. Methods and Findings: Participants were 1,450 (90.2% from total) individuals aged 60 years and over from the community-based Bambui (Brazil) Cohort Study of Ageing. From 1997 to 2007, 521 participants died and 89 were lost, leading to 12,905 person-years of observation. Body mass index (BMI) and waist circumference (WC) were assessed at baseline and at the 3rd and 5th years of follow-up. Multiple imputation was performed to deal with missing values. Hazard ratios (HR) of mortality for BMI or WC Conclusions: The usual BMI and WC cut-off points should not be used to guide public health and clinical weight control interventions in elderly in Brazil.