Background: The phenomenon of the spontaneous disappearance of herniated discs is well known.
Case Report: The case of a 74-year-old male presenting with a large disc herniation at L5-S1, experiencing moderate sciatic pain, and having the straight-leg-raising test positive at 30° is presented. The disc herniation was documented by computed tomography. He was treated conservatively with medication and physical therapy. One year later the patient was clinically reevaluated. He proved to be symptom-free and the follow-up computed tomography revealed spontaneous disappearance of the herniated disc fragment. The disc regression could have been due to dehydration, resorption as a result of an inflammatory reaction, or retraction into the intervertebral space.
Conclusions: This report discusses the three aforementioned possible explanations and underlines the need for limiting surgical treatment strictly to patients with neurological deficits, severe unremitting leg pain despite conservative measures, and repeated time loss from work.

Keywords: Intervertebral Disc - radiography, Intervertebral Disc Displacement - radiography, Lumbar Vertebrae - radiography, Remission, Spontaneous, Tomography, X-Ray Computed