Introduction and Aims. Approximately 25% of the Australian population was born abroad, yet there has been very little tobacco control aimed at culturally and linguistically diverse communities and limited data exist on smoking among Australian migrants. The aim of this study was to compare smoking characteristics of Australian migrants (in terms of place of birth and age migrated) to those of Australian-born residents. Design and Methods. A cross-sectional analysis of self-reported questionnaire data from 53 207 women and 48 777 men aged 45 years or over in The 45 and Up Study in Australia (2006-2008) was performed. Results. 52.6% (95% confidence intervals 52.1-53.0) of men and 35.5% (35.1-35.9) of women reported ever being a regular smoker and 7.6% (7.4-7.8) and 7.3% (7.1-7.5) reported current smoking, respectively. Compared with Australian-born men, a higher proportion of men born in Europe, North Africa and the Middle East were current smokers, with odds ratios adjusted for age, income, education and place of residence (OR; 95% confidence intervals) ranging from 1.30 (1.16-1.45) to 1.96 (1.49-2.58). Compared with Australian-born women, a lower proportion of women from East (0.21; 0.12-0.36) and Southeast Asia (0.38; 0.26-0.54) were current smokers and a higher proportion of women from New Zealand (1.45; 1.17-1.79) and the UK/Ireland (1.25; 1.12-1.40) were current smokers. Among women born in Asia, the risk of smoking increased significantly the younger they migrated to Australia. Duration smoked and amount smoked per day were primarily lower among migrants than Australian-born. Conclusions. Smoking prevalence varies substantially across cultural subgroups. Understanding smoking dynamics across diverse cultural groups will assist in better targeting of tobacco control programs. [Weber WF, Banks E, Sitas F. Smoking in migrants in New South Wales, Australia: Report on data from over 100 000 participants in the 45 and Up Study. Drug Alcohol Rev 2010;30:597-605]