This study focused on mediating and moderating processes underlying the relationship between work hours and well-being. Questionnaire data from 292 female employees in two UK public sector organizations were analysed. Drawing on effort-recovery theory and published empirical findings, it was hypothesized that work-family interference (WIF) would mediate the relationship between work hours and measures of well-being (psychological distress and family satisfaction), and that work-time control would moderate the association between work hours and WIF Hierarchical regression analyses showed that, after controlling for demographic variables, neuroticism, and job demands, WIF mediated the effect of work hours on family satisfaction, although no evidence of mediation was found for the psychological distress outcome measure. Work-time control moderated the relationship between work hours and WIF; higher control buffered the effect of longer hours on WIF. These findings add to the literature on the role of WIF in the effort-recovery process by showing that longer work hours are not necessarily associated with higher work family interference, and hence with poor recovery and impaired well-being. Instead, having a degree of control over work hours moderates the first link in this process. Thus, the provision by employers of some flexibility and control over work hours may help to reduce the potential negative impact of long work hours on employees.