This article prospectively examined the patterns of change in couples' family and friend networks and supports across the transition to parenthood as well as stability in individual differences over time. Additionally, parental adjustment and depression were examined with respect to changes in couples' social systems. Participants included a total of 137 couples recruited prior to the birth of their first child from prenatal clinics in rural North Carolina. Couples were interviewed about their social networks and supports at four different time periods: prenatally and when target children were 3, 12, and 24 months of age. Couples also completed measures of depression and adjustment at each of the time periods. Across-time correlations computed for the social network, support, and parental functioning variables revealed that there was considerable stability in the rank ordering of husbands and wives from the prenatal period through 24 months postpartum documenting continuity in parental networks in the context of change. However, growth curve analyses revealed dynamic changes in mothers' and fathers' social systems during this transition and that many of these changes were related to parental adjustment and depression. The discussion highlights the contribution of these data to understanding continuities and discontinuities in mothers' and fathers' social networks over time.