Background: Pediatric rheumatic diseases (PRDs) are a group of chronic disorders that start in childhood and are characterized by periodic exacerbations and remissions of symptoms, with limitations in family, school, and social activities. The aim of this study was to detect differences in parents’ psychological adjustment and emotion regulation strategies, and parent-reported children’s adjustments in families of children with active and inactive PRDs. Methods: Fifty-four parents (38 mothers and 16 fathers) of children with PRD were recruited from a pediatric unit. Disease activity was evaluated by their pediatric rheumatologist, while parents’ depressive and anxiety symptoms, emotion regulation strategies, and children’s emotional difficulties and hyperactivity–inattention symptoms were assessed through a web-based survey. Results: Parents of children with active PRDs reported higher levels of their child’s emotional difficulties and hyperactivity–inattention symptoms. Linear regression analysis demonstrated that having a child in the active phases of PRD and lower use of cognitive reappraisal lead to higher children’s emotional symptoms, while active disease, low use of cognitive reappraisal, and greater expressive suppression were associated with higher hyperactivity–inattention symptoms. Our study highlights that children with PRDs and their parents may be at increased risk for psychological problems, especially during the active disease phase, highlighting the importance of a multidisciplinary approach.