Findings regarding ethnic differences in eating disorder diagnoses and risk factors have been mixed. This study evaluated whether there are ethnic differences in eating disorder prevalence, risk factors, and the predictive relations of the risk factors to future eating disorder onset. We used a large sample of young women followed longitudinally over three years to increase sensitivity to detect differences and to provide the first test of ethnic differences in the relation of risk factors to future onset of eating disorders. Females with body image concerns (N = 1177) were recruited from high schools and colleges for trials of a body acceptance eating disorder prevention program. They completed surveys and interviews at baseline and at 1-, 6-, 12-, 24-, and 36-month follow-up. Significant differences between ethnic groups were found for two of the 13 baseline risk factors: thin-ideal internalization and body mass index. No significant differences in later onset rates among ethnic groups were found. There were also no reliable ethnic differences in the relation of risk factors for future eating disorder onset. These findings suggest that eating disorders affect ethnic minorities as much as Whites and that there are more overlapping risk factors shared among various ethnic groups than differences.