The objective of this study was to determine the clinical and laboratory characteristics, psychiatric manifestations and magnetic resonance imaging (MRI) findings in children and adolescents with Sydenham chorea (SyC). The imaging examination was repeated 1 year after the acute phase of SyC. There were 19 patients with a mean age of 11.7 years and a predominance of females (79%);68% had generalized chorea and 53% moderate chorea. SyC presented as an isolated manifestation in 74%. No association between SyC and obsessive-compulsive disorder was found. Mental health problems were present in 45% of the patients. MRI analysis revealed persistent alterations in the caudate nucleus in three patients (16%), who presented recurrent episodes of chorea during the study. In one patient, MRI revealed the presence of nodular heteropathy close to the caudate nucleus region. We conclude that attention problems can be associated with acute clinical features of SyC and persistent alterations in the basal nuclei, evidenced by MRI, can be found in some patients who tend to suffer prolonged attacks and a greater number of recurrences.