We draw on gender theory and neo-institutional theory to examine the impact of workplace characteristics and family demands on negative job-to-home and home-to-job spillover. Our multivariate analyses of the 1997 National Study of the Changing Workforce data indicate that family-supportive workplace cultures reduce negative spillover in both directions, whereas the availability of company policies, such as dependent care benefits and flextime, do not. Our results also show that family demands increase spillover more for women than for men. Our findings suggest that the atmosphere of the workplace is more important than the availability of company policies in reducing negative spillover.