Symptomatic degenerative disc disease (DDD) may lead to significant deterioration of quality of life and increased disability. Intradiscal thermal annuloplasty (IDTA) is a minimally invasive treatment for painful DDD. We hypothesized that there may be an improvement in pain scores and the pain disability index (PDI) of patients who have multilevel DDD after IDTA. Patients 24-66 yr old, male and female with multilevel DDD (MDDD) and matched 1 or 2 level DDD (1,2-DDD) patients were enrolled in the study. Visual analog pain scale (VAS) score and PDI were observed for 12 mo. The 1,2-DDD patient group had a 2.5 +/- 2.4 VAS score at 12 mo after annuloplasty compared to 7.7 +/- 2 before the procedure. The MDDD VAS score was 4.9 +/- 2.9 at 12 mo compared to 7.4 +/- 1.8 before the procedure. Similar improvements in PDI were found. The pain relief and PDI were significantly better in patients with 1,2-DDD than in the MDDD group (P = 0.0037 and P = 0.041, respectively). We concluded that IDTA is an effective treatment of discogenic pain and that the number of discs affected by degeneration is an important determinant of the procedure outcome.