Smoking causes cardiovascular and respiratory diseases, cancers and diabetes, and it has been a leading risk factor for death globally. Despite the availability of smoking cessation services locally, most smokers do not use such services. Workplace is one of the most convenient platforms to provide smoking cessation services and over 55% of smokers are employed according to the local population-based survey. However, the effectiveness of a smoking cessation programme conducted in workplace is yet to be examined in Hong Kong, and the attitudes and practices of corporations in promoting smoking cessation are not clear. Thus, this study aims to examine the employers'/managerial staff's knowledge, attitudes and practices in promoting smoking cessation in workplace and evaluate the smoking behaviours of participants before and after attending a smoking cessation intervention.