Loss of conjugate horizontal eye movements is usually due to a lesion in the pons (tumour, vascular, M.S.). However, the condition may also be congenital, either isolated or as part of Moebius's syndrome. Three patients with congenital absence of all conjugate horizontal eye movements are described. In two of them a conjugate pendular nystagmus was observed. Two of the three patients suffered from progressive scoliosis. Congenital absence of all conjugate horizontal eye movements, associated with progressive scoliosis, probably forms a separate clinical entity.