Sjögren-Larsson syndrome is a rare genodermatosis described by Sjögren and Larsson in 1957 (28) and characterized by ichthyosis, spastic di- or tetraplegia and oligophrenia. In the case reported here a female child, born to consanguineous parents, presented at birth as a "collodion baby". Progressively, she developed an ichthyosiform and erythrodermic state and at the same time, after an episode of seizures, spasticity of the lower limbs set in. From then on, her acquisitions were very slow. Symptomatic treatment with retinoids (etretinate, 13-cisretinoid, etretinate again) was attempted repeatedly, but it only resulted in temporary improvement of the ichthyosiform state. Overall evaluation at the age of 6 years showed: i) persistence of the ichthyosiform and erythrodermic state; ii) growth retardation (-2 in stature); iii) spasticity of the lower limbs with difficulty in walking, and beginning of speech. Routine examinations gave normal results. Serum linoleic acid level was within normal limits. Electroencephalography displayed immaturity tracings without signs of epilepsy. Radiography of the skull was normal, and in particular there was no thickening of the sphenoid bone. Histological examination of the skin, outside or during treatment with retinoids, showed ortho- and parakeratosic hyperkeratosis, absence of granular layer, moderate hyperacanthosis, vacuolization of numerous acanthocytes in the uppermost layers and inflammatory infiltrates in the superficial dermis. All these abnormalities were confirmed by electron microscopy. Previously published series are reviewed. In most cases the patient is a "collodion baby" at birth and progressively develops ichthyosis, spasticity, psychomotor and growth retardation.(ABSTRACT TRUNCATED AT 250 WORDS)