A case of bacterial endocarditis complicated by paralytic pontine exotropia is reported. Magnetic resonance imaging clearly showed a rostral lesion of the paramedial pontine reticular formation and the medial longitudinal fasciculus. The occurrence of paralytic pontine exotropia is suggestive of ischaemia, and patients with this so-called "one-and-a-half syndrome" associated with signs of infection should be investigated for endocarditis.