Septic cerebral venous sinus thrombosis is a rare but often fatal complication caused by bacterial meningitis and paranasal sinusitis. We report a particular case of the sudden and unexpected death of a six-day-old infant from unrecognised acute meningitis that caused a thrombotic occlusion of the venous sinuses (with the particular involvement of the torcular Herophili at the confluence of sinuses) resulting in subdural haemorrhage. This case report alerts paediatricians and neonatologists to the importance of promptly considering a possible diagnosis of meningitis without delay to avoid the fatal complications described here. As in all cases of sudden infant death our case study underlines the need for a thorough autopsy, accompanied by histological analysis, in order to identify the causes of the underlying pathological mechanisms causing death and to ensure an adequate differential diagnosis.