Introduction and objectiveThe best-known long-term complications of Kawasaki Disease (KD) are coronary artery aneurysms. However, there are numerous case reports about other unusual chronic complications. These data are only anecdotal, and more systematic observation is missing. We aimed to detect and describe chronic non-cardiac complications of KD.Material and methodsWe surveyed parents of children with KD diagnosed between 2014 and 2019 by phone with the use of standardized questionnaire. Clinical data about the acute phase of the disease, treatment, outcome, and symptoms and signs observed within three months since KD diagnosis were recorded from the caregivers. We recruited children from 3 children’s hospitals in Warsaw and a support group on social media.ResultsNinety children met the inclusion criteria. Parents of 30 children (33%) reported some neurologic sequelae, with persistent irritability being the most common, followed by sleep disturbances, aggression, and chronic fatigue. Seventeen children (19%) suffered either arthralgia or unspecific pain in the upper and lower extremities. In nine children (10%), either atopic or seborrheic dermatitis began shortly after KD. Five children (6%) presented with ophthalmic complications.ConclusionsVarious unspecific complications may emerge after the acute phase of KD. Although correlation does not imply causation, and possible explanations of observed abnormalities are numerous, our data may enhance clinicians’ awareness of frequent and poorly understood findings observed after KD in children. It also might help reassure parents that what they observe lies within a range of common and usually transient KD sequelae.