<p>Youth with maladaptive personality traits often experience diminished quality of life (QoL) as well as difficulties in interpersonal relationships. The present study aims to investigate the mediating role of perceived social support and conflicts with parents in the link between maladaptive personality traits and QoL. The sample consists of 110 youth referred to outpatient treatment (<i>M</i>_age = 21.3 years; range_age= 16–29 years) from a mental health institute in the Netherlands who filled out various questionnaires. Results indicate that youth with higher levels of negative affectivity, detachment, and psychoticism experience a lower level of QoL. Additionally, higher levels of negative affectivity, detachment, disinhibition, antagonism, and psychoticism are related to less perceived social support from father, which in turn is associated with lower perceived QoL. In other words, social support from father was a significant mediator and accounted for 18% up to 94.4% of the variance of the direct effect. However, social support from mother and conflicts with both parents are not significant mediators. Findings demonstrate that the direct association between maladaptive personality traits and QoL is, to a substantial extent, explained by social support from father. Therefore, it is important to investigate interpersonal relations separately for father and mother.</p>