Summary. In a 38-year old patient affected by acute radicular syndrome magnetic resonance imaging (MRI), diagnosed a large dorso-medial herniation at L4/L5 segment. Upon application of the usual conservative therapy, during 3.5 months of conservative treatment, no clinical improvement was achieved. On the new MRI, made after the completion of physical therapy (the patient was treated for 30 days in a thermal resort), i.e. 40 days subsequent to the first MRI or 3.5 months after the onset of symptoms, no signs of natural regression of the herniation, i.e. changes in the size of herniation, were noted. After unsuccessful conservative treatment, neurosurgeon recommended a surgical procedure which was postponed by the patient for a definite period of time. In the meantime, the patient underwent a manipulative treatment. In the course of the manipulative treatment, a significant subjective and clinical improvement was reached. In the segment affected by the herniation, four rotational manipulations all together were carried out at the intervals of ten days. On the new MRI made upon the fourth manipulation, i.e. 40 days subsequent to the second MRI, an almost complete regression of the herniation was found which corresponded to the clinical outcome. A conclusion can be drawn that, by rotational manipulation, a reposi- tion effect has been achieved. The patient described in these papers does corroborate the viewpoint of several authors on effectiveness of rotational manipulation in patients suffering from lumbar disc herniation.