Background <p>Ballism is characterized by random, continuous, large amplitude, proximal, involuntary movement. It usually involves one side of the body (hemiballism). Ballism is attributed to metabolic, vascular, autoimmune, traumatic, drug-induced, or iatrogenic causes.</p> Objectives <p>To determine the frequency and characteristics of functional ballism.</p> Methods <p><b>Analysis </b>of consecutive patients with functional movement disorders (FMDs) and non-functional ballism.</p> Results <p>We present 8 patients (5 females) with functional ballism and compared them with 149 patients with other FMDs. Patients with ballism showed greater severity with a higher score in the Simplified Functional Movement Disorders Rating Scale (S-FMDRS): 25.63 ± 10.25 vs. 12.44 ± 9.42 (<i>P</i> &lt; 0.001). Patients with functional ballism had greater number of affected limbs, more common bilateral involvement, and lack of distal chorea compared with 9 patients with non-functional ballism.</p> Conclusion <p>Functional ballism is an uncommon form of FMD <b>with distinguishing features compared with non-functional ballism</b>.</p>