Background This study explores hypotheses linking church attendance to smoking prevalence, cessation, exposure to environmental tobacco smoke (ETS), and household smoking bans among Korean immigrants in California. Methods Data were drawn from telephone interviews with Korean adults (N = 2085) based on a probability sample during 2005–2006 in which 86% of those contacted completed interviews. Results Koreans who reported that they had attended church were less likely to be current smokers and to be exposed to ETS, and more likely to have quit smoking and to have a complete smoking ban than non-attenders after statistical controls for behavioral covariates. Discussion Whether or not participants reported attending church was associated with increased tobacco control practices. Public health interventions may profit by seeking to expand cooperation with religious congregations to facilitate efforts to promote healthy lifestyles among immigrant populations beyond the influences of church attendance.