This article presents three cases of severe medullar lesion following trauma, resulting in tetraplegia and severe spasticity, and evaluates the safety and efficacy of treatment with intrathecal baclofen. In order to evaluate the patients' reaction to intrathecal baclofen, they were tested with trial doses of baclofen via a spinal tap prior to implanting the pump. This treatment brought a significant reduction of rigidity and spasticity for more than eight hours in all three cases rated according to Ashworth and Penn Spasm Frequency scales. A programmable infusion pump with an intrathecal catheter for administration of baclofen was then implanted in all three patients. The patients underwent neurological checkups every three months. They all showed satisfactory clinical improvement with progressive adjustments to the baclofen doses. No serious complications have been observed