This study examined the interpersonal and psychological functioning of expectant and nonexpectant adolescent couples. Interpersonal processes were assessed using the Structural Analysis of Social Behavior (L. S. Benjamin, 1974) and psychological functioning was assessed using the Diagnostic Interview for Children and Adolescents--Revised (W. Reich, 1991). Compared with their nonexpectant peers, expectant couples exhibited higher rates of negative interpersonal processes, including demand-withdraw behaviors and lower rates of positive interpersonal processes. Expectant males reported higher rates of behavior disorders, substance use disorders, and internalizing disorders than nonexpectant males. Higher rates of substance-use disorders mediated the effect of expectancy status on demand-withdraw behavior. Results help clarify the links between the psychological risks associated with adolescent pregnancy and the interpersonal functioning of young expectant couples.