When trying to balance work and family responsibilities, many workers experience conflict between these two roles. Although role commitment has been viewed both as contributing to and alleviating conflict, this relationship has not been fully tested. Using a sample of female nurses and police officers, we examined the direct and indirect relationship of role commitment with work-spouse and work-parent conflict. Increased work-spouse conflict was associated with "decreased" spouse commitment. Increased work-parent conflict was associated with "increased" parent commitment but with "decreased" spouse and job commitment. Job commitment moderated the relationships between irregular work schedules and work-spouse conflict and between job control and work-spouse conflict. Parent commitment moderated the relationship between irregular work schedules and work-parent conflict. These results suggest that, depending on the role, commitment may either alleviate or exacerbate conflict.