The authors present a case of an infant boy, otherwise healthy, who presented with acute irritability and obtundation. A head computed tomography scan revealed massive intracerebral hemorrhage. Investigations of the etiology revealed abnormal clotting times and reduced activity of all vitamin K-dependent factors. All etiologies of vitamin K deficiency were ruled out except malabsorption. The diagnosis of cystic fibrosis was confirmed by sweat chloride and genetic testing. Cystic fibrosis could present with cerebral bleed and should be considered in its differential diagnosis when other etiologies are not clear, as the other manifestations of vitamin K deficiency could be very subtle and unnoticed. Screening and early diagnosis of cystic fibrosis may prevent serious complications.