Botulinum toxin A (BTX-A) was used in adult cerebral palsy patients for chronic pain treatment. Five patients (quadriplegia 3, diplegia 1, and athetosis 1 with an average age of 47) were all classified as GMFCS level IV. As a treatment for neck and trunk muscle pain, BTX-A injections were administered with a total dose below 6 units per kilogram of body weight. To investigate the efficacy of BTX-A, the Visual Analogue Scale and Modified Tsui Scale were used to evaluate the patients before and at regular monthly follow-ups after their injections. We found significant improvement in the Visual Analogue Scale scores at 1 month after initial injection and also found the same difference at the second injection. Also, although we found improvement in the Modified Tsui Scale scores at 1 month after injection, these improvements did not last as long as the Visual Analogue Scale improvements. BTX-A has been used in a growing number of indications for the treatment of muscle spasticity including blepharospasm, facial spasm and spasmodic torticollis. We found that BTX-A may also be useful in treating patients with cerebral palsy suffering from chronic pain.