Tennis elbow is a common painful condition, which is typically seen in patients whose activities involve repeated forceful extension of the wrist, and can lead to a chronic pain syndrome with absenteeism. Tennis elbow is thought to be due to repetitive strain of the common tendon at the origin of the wrist extensor muscles, which may result in microscopic tears of the aponeurosis followed by a local inflammatory reaction in the tendon fibres close to the lateral epicondyle. Characteristically there is localised tenderness around the lateral epicondyle, and pain can be reproduced by resisted extension of the wrist or middle finger with the elbow in a straight position. The condition usually responds to conservative treatment including anti-inflammatory drugs, physiotherapy, or injection of corticosteroid into the tender area. If conservative treatment is insufficient, surgical treatment is needed which consists of relieving the tension in the tendon by detaching the origin of the common extensor muscle from the lateral epicondyle. We report the treatment of chronic tennis elbow with botulinum toxin, which is now widely used for neurological disorders, such as spasmodic torticollis, blepharospasm, hemifacial spasm, and dystonia. 1 Jankovic J Mitchell FB Therapeutic uses of botulinum toxin. N Engl J Med. 1991; 324: 1186-1194 Crossref PubMed Scopus (732) Google Scholar Since resisted extension of the middle finger is one of the most painful tests in chronic treatment-resistant tennis elbow, we treated the extensor digitorum communis III and IV muscle. In writers cramp this muscle has successfully been treated with 30–40 units botulinum toxin leading to full paresis. 2 Tsui JKC Bhatt M Calne S Calne DB Botulinum toxin in the treatment of writer's cramp: a double-blind study. Neurology. 1993; 43: 183-185 Crossref PubMed Google Scholar