Objective: To examine the effects of occupational therapy intervention on hand function after botulinum toxin injection in a patient with dystonia. Method: The subject was a 41 year old female and the study was carried out from February 25th to May 24th in 2002. The Jebsen Hand Function Test and Nine Hole Peg Test were used for assessment, and also hand and finger powers were assessed by grip strength, lateral pinch strength and three jaw chuck pinch strength. The scores were obtained during occupational therapy sessions at 4 weeks and 12 weeks after the injection. Modified Ashworth Scale was employed to grade spasticity before the injection, at 4 weeks, and 12 weeks after the injection. Results: Among the subtests of Jebsen Hand Function Test, the speed increased in the writing (15.4%), turning cards (64.4%), simulated feeding (92.0%), moving empty large cans (30.0%) and moving weighted large cans (41.6%), however, the speed of other subtests which were checkers(-26.8) and picking up small objects (0.0%) did not increase. The performance on Nine Hole Peg Test did not change (0.0%). Hand power of grip strength increased by 275%. Finger power increased in lateral pinch strength (40.0%) and three jaw chuck pinch strength(150.0%). Based on Modified Ashworth Scale, spasticity decreased from grade 4 before the injection to grade 1 at 4 weeks and 12 weeks after the injection in wrist and fingers. Conclusion: Occupational therapy intervention after botulinum toxin injection can improve the hand function in a patient with dystonia.