Objective of the study was to examine how cognitive emotion regulation strategies were related to psychological maladjustment in adolescents with a chronic disease. The sample consisted of adolescents with a diagnosis of Juvenile Idiopathic Arthritis (JIA). A self-report questionnaire was used to assess Internalizing problems and Quality of Life. The specific cognitive emotion regulation strategies that were used in response to the disease were measured by the Cognitive Emotion Regulation Questionnaire (CERQ). Correlations and Multiple regression analyses showed that Rumination and Catastrophizing were the most important "predictors" of psychological maladjustment in adolescents with JIA, suggesting that they should be considered as maladaptive cognitive emotion regulation strategies in response to a chronic disease such as JIA. Challenging these maladaptive cognitive emotion regulation strategies may therefore play an important role in intervention strategies. (Contains 1 table.)