Flexor and extensor spasms associated with severe spasticity frequently cause pain and suffering in neurologically impaired patients, and greatly interfere with comfort and activities. When high doses of oral medications are necessary to keep the symptoms under control and are poorly tolerated, the long-term spinal-selective intrathecal infusion of baclofen by means of implanted drug pump and catheter is a safe, efficient and reversible alternative to destructive surgical procedures. Between September 1991 and March 1995, intrathecal baclofen was infused in 18 selected patients out of a series of 42 severely disabled spastic cases. We report here our preliminary experience with the criteria of selection, the initial intrathecal bolus test and the long-term benefit of the selected patients. Our results confirm the dramatic immediate and long-term benefit reported in other series. After a period of treatment of 1 to 42 months, 13 patients had a complete disappearance of their spastic symptoms without any oral treatment, one patient kept unchanged clonus despite the use of low-dose oral treatment and another one a severe, not improved dysuria although in both of them hypertonia and spasms were abolished. Finally, 2 patients had important joint stiffness slightly impairing the benefit from the treatment. None of the 18 patients had central side-effects related to baclofen. With time, a slight increase in daily dose (inferior to 10%) was necessary in most patients.