We compared the diagnostic accuracy of lumbar facet blocks guided by either conventional fluoroscopy or CT fluoroscopy (CTF). Seventy-one blocks were performed with conventional fluoroscopy, and 58 were performed using CTF. Pain scores were measured before and after the procedure. The CTF group had a greater percentage decrease in pain (79.5% +/- 31.1%) than did the conventional fluoroscopy group (55.5% +/- 38.0%; P < .0005). We conclude lumbar facet blocks by using CTF guidance results in greater diagnostic accuracy than do conventional fluoroscopy.