The prevalence of disordered eating among college students was assessed at the beginning and the end of the freshman year. The study aimed to identify factors related to worsening of disordered eating during the year. Questionnaires were completed by 590 males and 450 females at baseline and 546 males and 403 females at follow-up. At baseline, the prevalence of bulimia nervosa was 3.8% for females and 0.2% for males. The prevalence of disordered eating symptoms was considerably higher. The prevalence of bulimia nervosa at follow-up was virtually unchanged. However, many students experienced an onset of disordered eating during the year. Analyses of changes during the year revealed that worsening of disordered eating among females was associated with increasingly dysphoric feelings about weight, decreased ratings of their attractiveness, high perceived stress, increased weight dissatisfaction, and increased ineffectiveness.