Second language (L2) gains during study abroad have been related to several variables including length of stay (Llanes, 2011), language use (Martinsen, Baker, Dewey, Bown, & Johnson, 2010), and social network development (Isabelli-García, 2006), among others. However, most studies have investigated only a few predictors in single study abroad programs. While these findings are helpful, larger scale studies are needed to better understand the variables that contribute to L2 gains across several different cultures and learner groups. The current study examines predictors of L2 gain of more than 100 native English speakers who participated in study abroad in Mexico, Spain, France, Egypt, Russia, and China. Participants were asked to complete an ACTFL Oral Proficiency Interview at the beginning and end of their study abroad program. Participants were then divided into “gainers” and “non-gainers,” or those who did or did not make significant language gains from pre- to posttest. Their language gains from pre to posttest were compared to several predictors: personality (measured by the NEO Five-Factor Inventory), social networks (size, dispersion, density, etc.), intercultural sensitivity (measured by the Intercultural Development Inventory), amount of second language use, gender, and age. Results suggest that many students were able to make gains in language, in each of the programs, and that the strongest predictors of L2 gains were cultural sensitivity and social network variables.