A 34-year-old woman with cerebral palsy was admitted to our hospital because of increased spasticity. She showed spastic quadriparesis with partially inhibited range of motion of the lower limbs. Her modified Ashworth Score (MAS) was 2 for the upper limbs and 3 for the lower limbs. Radiography showed mild scoliosis, but magnetic resonance imaging did not show any compression of the spinal cord. An abdominal computed tomography scan revealed urinary retention and a large bladder diverticulum. A urological assessment was performed, and an indwelling catheter was placed in the bladder. In addition to urological management, non-invasive spasticity management was performed, and her MAS was reduced to 1＋and 2 for the upper and lower limbs, respectively. After these treatments, the patient was able to resume self-care activities.