Guided by the life course perspective, this study investigated the developmental antecedents of contact, closeness/warmth, and negativity in young adults' relationships with their parents. Taking the developmental systems approach, we considered interindividual differences in not only initial levels of parenting quality in early adolescence (Grade 6) but also developmental changes in parenting quality across adolescence (Grades 6-12) as predictors of young adult-parent relationship quality. Data were from a large sample of young adults (N = 1,631; M[subscript age] = 22.84; 57% female; 90% White; 25% received free/reduced-price school lunch in Grade 6) followed from the fall of Grades 6 to 12 at eight time points, plus a young adult assessment. Using multivariate latent growth curve modeling, we identified a nuanced pattern of predictors of the three relationship dimensions. Higher initial levels of and lower rates of decline in parental involvement across adolescence predicted more young adult contact with mothers and fathers. Higher initial levels of parental warmth and parental involvement, as well as lower rates of decline in parental warmth, predicted greater closeness/warmth with mothers and fathers in young adulthood. Higher initial levels of and lower rates of decline in effective discipline predicted less young adult negativity toward mothers and fathers. These results held even when accounting for important adolescent and young adult covariates (adolescent sex and race, adolescent family income and structure, adolescent aggressive behavior tendencies, young adult living arrangement). The study offers new insights into how parenting practices in adolescence contribute to parent-child relationship in young adulthood.