A characteristic headache occurs in about 36–55% of patients after lumbar puncture, and many of these patients need bed rest for one or more days to get relief. In a double-blind randomized trial we compared a new 22-gauge atraumatic puncture needle with the most widely used 20-gauge “conventional” needle. In 49 patients randomized to the atraumatic needle, post-lumbar puncture headache occurred in 6%, whereas in the 50 patients randomized to the conventional needle this occurred in 32% (p=0.001). On the basis of these results we recommend use of the atraumatic needle in order to diminish the frequency of post-lumbar puncture headache.