In this paper we examine smoking prevalence and frequency among Asian and Latino U.S. immigrants, focusing on how gender differences in smoking behavior are shaped by aspects of acculturation and the original decision to migrate. We draw on data from 3,249 immigrant adults included in the 2002-2003 National Latino and Asian American Study. Findings confirm the gender gap in smoking, which is larger among Asian than Latino immigrants. While regression models reveal that gender differences in smoking prevalence, among both immigrant groups, are not explained with adjustment for measures of acculturation and migration decisions, adjustment for these factors does reduce gender differences in smoking frequency to non-significance. Following, we examine gender-stratified models and test whether aspects of migration decisions and acculturation relate more strongly to smoking behavior among women; we find that patterns are complex and depend upon pan-ethnic group and smoking measure.