Cerebral paradoxical embolism has not until now been described as a cause of cryptogenic stroke in newborn infants. A male infant was born at 27 weeks 2 days' gestational age by emergency Caesarean section in a twin pregnancy because of intrauterine growth retardation and absence of diastolic flow in the twin. His birthweight was 950g (50th centile). Apgar scores were 7 and 8 at 1 and 5 minutes respectively. At 17 days of life he showed sudden respiratory distress and signs of encephalopathy. Presence of deep venous thrombosis, patent foramen ovale (PFO), and clinical progression suggested paradoxical embolism which were confirmed by neuroradiological findings. The high incidence of PFO and central venous catheter-related deep venous thrombosis in newborn infants suggest that paradoxical embolism is probably a more common complication than has been thought.