Sydenham’s chorea is a delayed complication of group Aßhaemolytic streptococcal infections and forms one of the majorcriteria of acute rheumatic fever.It is characterised bychorea, muscular weakness, and a number of neuropsychiatricsymptoms. It is considered to be an autoantibody mediated disorderwith the evidence suggesting that patients with Sydenham’schorea produce antibodies that cross react with streptococcal,caudate, and subthalamic nuclei.However, documented evidenceof previous streptococcal infection is found in only 20%–30%of cases. It has a goodprognosis for full recovery so treatment is not warranted inmost cases. Following case is a high school student presented with progressive changes in his handwriting during two months before. Chief complaint of this 15-year-old boy was difficulty in writing at classroom. His physics notebook has been shown as interesting figures.