While obesity continues to be a significant health issue, the relationship between body weight and mortality risk remains unclear. Research notes the strong association between obesity and higher mortality risk, along with the “protective” effect of higher weight for some groups. Few studies have examined this relationship when stratified by socioeconomic status, especially when considering premature mortality among working-aged adults. Using recent National Health Interview Survey data, this study examines variation in BMI-associated premature mortality risk across different levels of education. Results indicate overweight and class I obesity are associated with lowest mortality risk among the lower-educated. Conversely obesity is associated with increased mortality risk for individuals with a college education or greater, while overweight is not associated with reduced risk. Thus, obesity may pose a greater relative health risk in more advantaged groups, such as the highly educated, while other socio-behavioral factors account for premature mortality among lower-educated individuals.