The detrusor-sphincter dyssynergia (DSD) is a common and significant problem for patients with spinal cord lesions. If not treated, DSD can lead to severe and potentially lethal complications (urinary tract infections and renal damage). BTX inhibits acetylcholine release at the neuromuscular junction, producing muscle chemical denervation in the site of injection. The aim of this preliminary study was to test the safety and the effects of BTX injection in the spastic urethral rhabdosphincter in patients with DSD. Five patients (3 M, 2 F; mean age 43 years, range 22-56) with DSD entered the study. Videourodynamic parameters were controlled before BTX injection at 10 days, at 3 and 6 months after infiltration. The aim of this preliminary study was to test the safety and the effects of BTX injection in the spastic urethral rhabdosphincter in patients with DSD. The post void residual urine volume, the maximum pressure of emptying and the maximum pressure of urethral closure are reported in Tab. II-III-IV. Patients reported subjective improvement of bladder emptying and improved quality of life. No adverse effects related to pharmacological activity of BTX or to infiltration procedures were observed.