The relation between perceived interpersonal experiences of discrimination and measures of obesity is of great interest to many. This study examined the relation between changes in waist circumference and changes in perceived interpersonal everyday discrimination using the 1995-2004 Midlife Development in the United States cohort study (N = 1,452). After controlling for potential confounding variables that assessed behavioral and sociodemographic characteristics, sex-stratified ordinary least squares regression analyses suggested that the waist circumference of adult males who reported consistently high levels of interpersonal everyday discrimination increased 2.39 cm more than that of adult males who consistently reported low levels of interpersonal everyday discrimination (P < 0.05). Similarly, the waist circumference of adult females who reported an increase in interpersonal everyday discrimination increased 1.88 cm more than that of adult females who reported consistently low levels of interpersonal everyday discrimination (P < 0.05). These findings suggest that perceived interpersonal everyday discrimination may be associated with an increase in waist circumference over time among adults in the United States.