California's Smoke-Free Workplace Act was extended to include bars in 1998. While the majority of bars in the state have become smoke free, in many bars patrons and staff continue to smoke despite the law. The authors present findings from a study which assessed cultural factors related to continued smoking in bars in the city of San Francisco. In bars serving primarily Irish migrants, tight-knit relations within the local Irish bar community together with a reluctance to be the first Irish bar to ban smoking were found to contribute to continued indoor smoking. The findings illustrate challenges to implementing tobacco control policies within ethnic subpopulations and particularly highlight the importance of considering how cultural dynamics within subpopulations may help or hinder such policies.