Study findings indicated an increased vulnerability regarding recurring sexual assault victimization, and racial and ethnic disparities within sexual assault victimization based on immigrant status. Immigrant status conferred risk among adolescent girls aged 15 and younger, African-American adolescent girls, and sexually active Hispanic girls. No differences were found in sexual assault victimization based on acculturation. The relationship of immigration to adolescent sexual assault victimization remains unclear despite assessment of immigrant status on several categories of adolescent risk behaviors. No representative research to date has assessed whether there is heightened or diminished vulnerability for sexual assault among immigrant compared with nonimmigrant girls, or less acculturated compared with more acculturated girls; nor an examination of these relationships within major racial and ethnic groups. This study assessed associations between immigration and acculturation with the outcome variable sexual assault, among a large sample of high school girls in Massachusetts. The total number of female participants (N = 5,919) was from the 1999, 2001, and 2003 Massachusetts Youth Risk Behavior Survey. Tables, references