This study investigated how information about weight-control effort influences obesity stereotyping. 763 participants (583 women, 172men, 8 undeclared) read a brief vignette about a fictional woman who was described as either obese and of unhealthy weight or of normal/healthy weight, and who either did or did not make efforts to control her weight through diet and exercise, and then rated her across a number of personal characteristics. MANOVA revealed that the woman described as obese was rated as more likely to suffer from an illness in the future, more unattractive, weak-willed, lazy, unhappy, emotional, unpopular, unintelligent, unsuccessful, and less likely to find a romantic partner. Weight-control effort improved ratings of the normal-weight woman but made no difference to, or worsened, ratings of the woman described as obese. These results highlight the prevalence and persistence of obesity stereotypes, and are discussed in relation to attributional models of prejudice.