Using a high-risk community sample, multiple regression analyses were conducted separately for mothers (n = 416) and fathers (n = 346) to test the unique, prospective influence of parental negative affect on adolescent maladjustment (internalizing symptoms, externalizing symptoms, and negative emotionality) 2 years later over and above parental alcohol and affective disorders, major disruption in the family environment, and parenting. Adolescent sex was tested as a moderator. Results indicated that maternal (but not paternal) negative affect had a unique, prospective effect on adolescent internalizing symptoms in girls and negative emotionality in both sexes but did not predict adolescent externalizing symptoms. Findings demonstrate that mothers' negative affect may have unique effects on adolescent adjustment that are separate from the effects of clinically significant parental psychopathology, parenting, and disruption in the family environment. (Contains 1 figure, 4 tables and 7 footnotes.)