The aims of this study were threefold. Firstly, to analyze the psychometric properties of the Polish-language Pediatric Outcomes Data Collection Instrument (PODCI) questionnaire in the self-report Adolescent Outcomes Questionnaire (adolescents, 11-18 years of age) and in the parent-report Adolescent Outcomes Questionnaire (completed by a parent or guardian of an adolescent aged 11-18 years). Secondly, to determine the level of agreement between parents and adolescents in rating dysfunction in juvenile idiopathic arthritis (JIA) and thirdly, to examine associations between psychological adjustments of patients to JIA and disease as well as their socio-demographic characteristics. The study sample consisted of 52 participants. 26 adolescents between the ages of 11 and 18 years with a diagnosis of JIA and 26 parents were considered for inclusion. Disease course was classified as pauciarticular (n = 12, 46.2%) and polyarticular (n = 14, 53.8%). Participants completed the PODCI (self- and parent- report) twice and the Strengths and Difficulties Questionnaire-25 (SDQ-25). Considering the distribution of results regarding PODCI normative scores, 73.1% of parents and 69.2% of patients scored below 50 on the Global Functioning Scale; that is lower than the average for the general healthy population. Regarding the parent report, the total score of the SDQ-25 equaled 11.86 (SD 2.66), whereas the patient report equaled 11.23 (SD 2.78). The study groups do not differ significantly in regards to either the PODCI or the SDQ-25 results. Parents and adolescents with JIA appear to hold very similar perceptions of patients’ health. Greater differences emerge as disease severity and age of patients increase. Excellent internal consistency, intrarater and test-retest reliability of the Global Functioning Scale have been confirmed in the Polish version of the PODCI, the questionnaire may therefore aid identification of patients reporting significant problems in this group.