To examine the effect of ethnicity on waterpipe smoking among college students.A cross-sectional study utilized data from University of Houston students through an online survey (n = 2334) from March to April 2011. The survey included questions on demographic characteristics (sex, age, race/ethnicity), tobacco use experience, risk perception, social acceptability and popularity. Multivariate logistic regression was used to determine predictors of waterpipe use with three outcomes: ever-use vs. no use, past-year use vs. no use and past-month use vs. no use.Half of the sample had previously smoked tobacco using a waterpipe, approximately a third in the past year and 12.5% in the past month. Significant predictors included Middle Eastern ethnicity, Middle Eastern friend, past cigarette or cigar use. Perception of harm was associated with less use in the ever-use model, while perceived addictiveness, social acceptability and popularity of waterpipes were predictors in all models.Our findings underscore the importance of developing culturally appropriate interventions to control waterpipe smoking among Middle Eastern Americans and those of Indian/Pakistani descent to curb further spread in US society, and highlight the importance of developing interventions that target the perceived addictiveness, social acceptability and popularity of waterpipe smoking.