Isolated motor disturbances in the paediatric population are uncommon presentations to the emergency department. Choreiform movements have a broad differential diagnosis and may present insidiously with progressive worsening of asymmetric clumsiness, hypotonia and dysarthria. The incidence of Sydenham's chorea (SC) caused by acute rheumatic fever (ARF) is very rare in developed countries. We report a previously healthy, vaccinated 9-year old male who presented to our ED with intermittent and progressive right sided clumsiness for four weeks. Physical examination findings showed dysdiadokinesis and dysmetric movements of the right side, which varied in intensity and were less pronounced on serial re-examination during the same ED visit. Basic bloodwork, MRI and MRA/V showed no abnormalities, and the patient was discharged home with urgent neurology follow-up. He re-presented to our ED four days later with worsening gait and inability to hold a pencil at school. He was subsequently diagnosed with chorea by the neurology team. The cause of chorea was later determined to be SC, and the patient's throat swab came back positive for group A-beta hemolytic strep (GAS) infection. We explore current literature regarding the various presentations of ARF, differential considerations in acute chorea, and diagnostic studies needed to determine the etiology of acute chorea. With the low incidence of chorea in developed nations, this diagnosis can be easily overlooked. We highlight the importance of this diagnosis, as well as primary and secondary treatment in ARF.