Two independent prospective longitudinal studies that cumulatively spanned the age interval from 4 years to 14 years used multiwave designs to investigate developmental associations between language and behavioral adjustment (internalizing and externalizing behavior problems). Altogether 224 children, their mothers, and teachers provided data. Series of nested path analysis models were used to determine the most parsimonious and plausible paths among the three constructs over and above stability in each across age and their covariation at each age. In both studies, children with poorer language skills in early childhood had more internalizing behavior problems in later childhood and in early adolescence. These developmental paths between language and behavioral adjustment held after taking into consideration children's nonverbal intellectual functioning, maternal verbal intelligence, education, parenting knowledge, and social desirability bias, as well as family socioeconomic status, and they applied equally to girls and boys.