The rank-order stability and cross-lagged relations between work-to-family conflict (WFC), family-to-work conflict (FWC), and psychological well-being were examined in two longitudinal studies with full two-wave panel designs. In Study 1 (n = 365), the time lag was one year, and in Study 2 (n = 153), six years. The Structural Equation Modeling showed that the stability for WFC was 0.69 over one and 0.73 over six years. The respective stabilities for FWC were 0.57 and 0.48. Cross-lagged relations were not detected between WFC/FWC and low psychological well-being (job exhaustion, marital adjustment, parental stress, and psychological distress), expected to exist on the basis of the integrative model of work-family interface [Frone, M. R., Yardley, J. K., & Markel, K. S. (1997). "Developing and testing an integrative model of the work-family interface." "Journal of Vocational Behavior," 50, 145-167.]. Instead, high job exhaustion preceded high psychological distress, both within one- and six-year time lags, and within a one-year time lag: low marital adjustment preceded high psychological distress, and high psychological distress preceded high parental stress. These findings supported the spillover perspective on work-family interface [Edwards, J. R., & Rothbard, N. P. (2000). "Mechanisms linking work and family: Clarifying the relationship between work and family constructs." "Academy of Management Review," 25, 178-199.]. (Contains 2 figures and 1 table.)