There is increasing evidence that dysfunctional personality traits, related to psychological maladjustment and psychopathology, can play an important role in a person's ability to cope with major stressful events. Relatively little is known about the specific effect of the emotional component on the relationship between maladaptive personality traits and psychological stress. Therefore, the aim of the present study was to investigate the relationship between the maladaptive personality traits of psychoticism, detachment, and negative affect, and psychological stress, considering the effects of COVID-19-related worries and emotional dysregulation. An online survey was administered to 1172 adult participants. A series of path analysis models showed that maladaptive personality traits (psychoticism, detachment, and negative affect) are related to psychological stress. COVID-19-related worries and emotional dysregulation partially explained this association. The results suggest that in the early months of 2022, during the reduction of government restrictions, although the world population was no longer in nationwide lockdown, the COVID-19-related emotional component could still explain, at least in part, the association between maladaptive personality traits and psychological stress.