Background: Rheumatoid arthritis (RA), the chronic autoimmune disease with several opinions about its aetiology, has affected more than 50 million people in the world. The aim of this 2008 study was to investigate the association between smoking and RA in Hamedan, a western city of Iran. Methods: As a case-control study, information from 130 cases and 130 controls, matched for age and sex, were collected by questionnaire and analysed using SPSS (chi-square, phi and Cramer tests). Results: From 130 cases, 80 cases were females and the rest were males. Statistical analysis showed that smoking less or more than 10 cigarettes daily has a significant association with RA in both sexes, together or separately (p < .05). However, there is no significant association between duration of smoking cessation within 2 years or more, and RA in both sexes (p > .05). This means that cigarette cessation at any time can be useful in RA prevention. Conclusion: Considering previous global investigations on this topic and the results of our study, it seems that smoking even low numbers of cigarettes affects the presence of RA and it is never too late to give up smoking.