A retrospective review was conducted to assess the effectiveness and safety of a temporary subarachnoid shunt to treat patients who have a leak of cerebrospinal fluid after a spinal operation. The shunt is percutaneously inserted in the lumbar spine and is removed after four days. This technique was used in nineteen patients over a ten-year period. Of the seventeen patients who had the shunt in place for the full four days, fourteen had resolution of the drainage of cerebrospinal fluid from the wound. One of two patients whose shunt was removed early also had a successful result. Eleven of the fifteen patients who were successfully treated were available for follow-up, and none had any adverse effects related to the original cerebrospinal-fluid leak or its treatment. The four patients who had a persistent leak were successfully treated with reoperation and direct repair of the dura. Eleven (58 per cent) of the nineteen patients had transient complaints of nausea and vomiting while being treated with subarachnoid drainage. Two of the nineteen patients had evidence of an intradural infection after placement of the catheter; the infection resolved in both patients after removal of the catheter and treatment with appropriate antibiotics. Closed subarachnoid drainage, when properly performed and monitored, is a reasonably effective and safe method for treating dural-cutaneous cerebrospinal-fluid leaks after a spinal operation. It may be considered as a non-operative alternative to the standard procedure of reoperation and direct repair of the dura. A good result is still possible in patients in whom this technique fails and who eventually need surgical management.