As an emerging human resource issue in business ethics, work-life balance has been gaining increasing attention from both practitioners and scholars in recent years. In response to the call of Kelliher et al. :97–112, 2019), we addressed the research gap by examining the WLB of Chinese knowledge workers under flextime arrangement and the impact of work-life supportive culture on work-life spillover of the workers. Specifically, we examined the relationships between three components of work-life supportive culture, namely managerial support, career consequences, (...) and organizational time demands, and two aspects of work-life spillover, positive and negative spillover, perceived by the workers. A quantitative survey with 35 employees in a software development company in Hong Kong was conducted. The results of structure equation modelling showed that managerial support was positively related to positive work-life spillover while organizational time demands was positively related to employees’ negative spillover. WLB needs of knowledge workers and the role of organizational culture in effective implementation of WLB policies were discussed, and several feasible WLB policies were suggested for managers. (shrink)