The present study examined the association between ethnicity, acculturation and leisure-time physical inactivity among East Asian and Caucasian women in Canada using the 2000--2001 Canadian Community Health Survey. The sample consisted of 762 East Asian and 31,504 Caucasian female adults aged 25 to 64 years. Multivariate logistic regression was performed to investigate the relationships.Results of the analysis showed that East Asian women were more likely to be inactive compared to Caucasian women, although not when the level of acculturation was statistically controlled. A higher level of acculturation was significantly associated with a low prevalence of physical inactivity only among East Asian women. East Asian immigrants, particularly those staying for 10 to 19 years in Canada, were likely to be inactive compared to their non-immigrant counterparts (OR = 4.5, CI = 1.81--11.1). Health promotion programs need to pay increasing attention to the cultural orientation and barriers towards physical activity among immigrant East Asian women.