The authors report a case of bilateral ptosis with miosis, paralysis of upward gaze and of smooth pursuit movements to the right, as well as a slowly regressive state of lassitude. This syndrome followed a haemorragic brain stem infarction. After a review of the pathophysiology of ptosis and of vertical eye movements, together with analysis of data provided by computerized tomography studies - since the case was not fatal - explanations are offered for each clinical sign and it is proposed that the lesion, a paramedian, slightly deviated to the right haemorragic focus in the midbrain, with a diameter of 15mm, might have involved several structures, namely the rostral interstitial nucleus of the medial longitudinal fasciculus, the mesencephalic reticular formation, as well as cortico-nuclear and sympathetic pathways.