Empathic accuracy, the ability to correctly perceive another's emotional state, is crucial for daily interactions. In parent-adolescent relationships, this process is complicated by developmental changes and evolving relational dynamics during adolescence. To date, it remains unclear whether and how relational factors, such as closeness, influence empathic accuracy in parent-adolescent dyads. A total of 112 parent-adolescent dyads (adolescent Mage = 14.13; 54.5% girls) participated in a 28-day daily diary study. The multilevel Actor-Partner Interdependence Model (APIM) was used to assess how baseline and daily perceived closeness—reported by both parents and adolescents—predicted parent and adolescent empathic accuracy in daily life. We found that parents and adolescents both showed empathic accuracy, but parents were more accurate than adolescents in detecting their partners' negative emotions. Interestingly, higher baseline and daily closeness were associated with lower empathic accuracy, especially for negative emotions. These associations emerged at both the actor and partner level: individuals who felt closer were less accurate themselves, and their partners were also less accurate. This pattern supports the motivated inaccuracy perspective, suggesting that emotional closeness may reduce motivation to attend to negative emotions—either to protect the relationship or due to overconfidence in mutual understanding. Our findings highlight the dynamic nature of emotional understanding in families and suggest that empathic processes may play a key role in navigating adolescents' growing need for autonomy within close parent-adolescent relationships.