The phenomenon of discordance between parents' and children's ratings of the child's mental health symptoms or of parenting behavior until recently has been treated as a problem of reliability. More recent work has sought to identify factors that may influence discordance, yet much remains to be learned about why informants' ratings of developmental phenomena are discordant and the meaning of such discordance. This study examined the extent to which discordance can be treated as a measure of the difference between two equally valid perceptions, and as such an indicator of the quality of the parent-adolescent relationship. One category of concordance and three patterns of discordance were derived from item-level differences in ratings of affection, control, and punitiveness provided by a diverse sample (53% female; 46% Hispanic-American, 35% African-American, 15% European-American, 4% another race/ethnicity) of 484 adolescents aged 12-20 years (M = 15.67, SD = 1.72) and their parents. Over and above adolescents' and parents' independent ratings of parenting, the discordance between these ratings was found to predict adolescent reports of anxiety and conduct disorder symptoms, as well as the quality of the parent-adolescent relationship. This was particularly true when adolescents and parents were discordant in their ratings of affection and when adolescents rated their parents higher on affection than did parents themselves. Implications of these findings and future research directions are discussed.