While associations with deviant peers are well understood to impact individual development, less is understood about the relationship between friendship quality and delinquency. Two criminological theoriessocial control theory and self-control theoryare able to offer an explanation for the latter relationship. Social control and self-control theories both premise that delinquents will have largely fractured, weak, and "cold and brittle" friendships. This study investigates how variations in perceptions of friendship quality are related to the delinquency, maternal attachment, school attachment, and self-control levels of both a participant and his/her close friend. To explore these relationships, the authors use a diverse (14 percent black; 18 percent Hispanic; 9 percent Asian) sample of 2,154 emerging adults within 1,077 friendship pairs (66 percent female). In each dyad, both members perceived the friendship's quality and reported personal markers of delinquency, social bonds, and self-control. Several series of multilevel models are estimated that regress each participant's friendship quality perception onto the participant's and their friend's delinquency, attachments, self-control, and demographic characteristics. Results show that delinquents have as intense, or more intense, friendships as non-delinquents. However, low levels of both actor and partner attachments and self-control are independently related to low friendship quality, and this is especially true for self-control. Supplemental analyses demonstrate that the effect of self-control on friendship quality may be reduced when individuals in dyads are delinquent. In conclusion, studies that address friendship quality without including characteristics of multiple members of the friendship are only capturing part of one's estimate of friendship quality. Abstract published by arrangement with Springer.