The authors set up a prospective study of the effect of conservative treatment on a ruptured lumbar disc herniation in 89 patients, between June 2008 and June 2010. Seventy-two patients (81%) improved, while the other 17 (19%) needed surgery. The JOA score (best possible result: 29) was found to be significantly improved in the 72 patients of the conservative group, at 1 month, 3 months, 6 months, 1 year and 2 years (t-test: p < 0.001). At final follow-up, after 2 years, 84.7% of the patients in the conservative group had a good or excellent result. However, if the 17 surgical cases were included, this proportion dropped to 68.5%. The volume of the protrusion decreased significantly in the 72 patients of the conservative group: from 1422.52 +/- 539.10 mm3 to 102735 +/- 585.51 mm3 (paired t-test: p < 0.001). There was a definite correlation, in the conservative group, between the final resorption rate on the one hand and the percentage of combined excellent and good results on the other hand (72 cases; Spearman rank correlation coefficient: r 0.01 = 0.470, p < 0.001).