This paper aims at elucidating to what extent patients with lumbago-sciatica in the presence of an herniated intervertebral disc, are inclined to describe their pain in a characteristic way. The material comprised 50 patients with clinical and radiological signs indicating herniation of the L4/5 or L5/S1 discs. The assessment of pain was performed by formal oral interview, focussing on spatial distribution and somatosensory dimensions of pain in various regions of the back and leg. In conformity with the fact that a range of sensible nerves are affected by the herniation pain description is represented by a variety of pain qualities. The pattern of pain description tends to exhibit certain characteristic traits: only half of the patients had low-back pain, and pain was most frequently occurring in the gluteal region, thigh and calf. The frequency of superficially localized pain tended to increase in the proximo-distal direction. Aching-like pain was the most common pain quality, and this variant of pain as well as flashing and jerking sensations were commonly reported in the gluteal region, thigh and calf. Warmth was most frequently experienced in these regions, cold sensations in distal parts. A feeling of punctate pressure was common in the gluteal region, incisive pressure and paraesthesia in the thigh and calf, and a cramp-like feeling in the calf region. Reduced sensibility was frequently experienced in distal parts and never in the lumbar region. Pain quality differs in patients with a short and a long duration of the actual attack of sciatica. The mapping of pain seems to represent a diagnostical aid. A high degree of homogeneity of the patients is required for pain description to be a valid and reliable instrument. The clinical application of pain mapping is to be shown through a paper-and-pencil administration of a questionnaire based upon the findings from this study.