Previous research has demonstrated the influence of family functioning on developmental outcomes but only a few studies have addressed the normative changes of family functioning during adolescence. While there is evidence that family adaptability is stable, findings regarding the development of family cohesion levels are controversial. The focus on the association of family functioning with parenting behavior has also been quite limited. Some studies have revealed that an authoritative parenting style is connected with better family functioning, but only a small body of research has analyzed the association with the main dimensions of parenting behavior. The current study investigated developmental trajectories of family adaptability and cohesion from adolescence to young adulthood. The impact of sex, number of siblings, marital status, socioeconomic status and parenting behavior was studied in a sample of N = 619 participants from a longitudinal Swiss study at two measurement times. Repeated measures ANOVAs and cross-sectional linear regression models were used to analyze the data. There was a significant developmental decline in perceived family cohesion but no change in adaptability from adolescence to young adulthood. In addition, there was a significant main effect of socioeconomic status on adaptability and of parental divorce on cohesion. Boys experienced a significantly steeper decline in family cohesion than girls. Adaptability and cohesion were predicted by perceived parental acceptance and psychological control at both measurement times while cohesion was also significantly predicted by perceived parental structure. The findings reflect normative developmental processes in the transition period.