A 3-year-old male with steroid-responsive nephrotic syndrome developed a rare complication, sagittal sinus thrombosis during an episode of gastroenteritis, while on steroid therapy. Anticoagulation, as assessed by partial thromboplastin time, was difficult to maintain, despite administering high doses of heparin, infusions of fresh-frozen plasma to provide antithrombin III, and, subsequently, maximum doses of warfarin (0.3 mg/kg per day). Despite these problems the child made a complete neurological recovery.