Cerebral sinus vein thrombosis is rare in children. So far, only three other cases have been reported in a child with diabetes mellitus. This 10 year-old female presented with classic signs of diabetic ketoacidosis which resolved with standard fluid and insulin therapy. Headache persisted despite biochemical improvement and 6th nerve palsy became evident on Day 3. On Day 5, sudden deterioration in mental status to the point of coma with loss of airway protective reflexes prompted repeat imaging including magnetic resonance venography which demonstrated thrombosis of the superior sagittal, straight, right transverse, right sigmoid and proximal posterior aspect of the left transverse sinuses. Selective thrombolysis using rTPA was performed emergently. Complete lysis of the thrombosed veins was observed within 35 hours. Low molecular weight heparin was continued for 6 months. Significant clinical improvement was noted within 48 hours of the procedure. Six weeks later recovery was complete. Complete hematological work-up for hypercoagulable state revealed a heterozygous mutation of the prothrombin gene (G20210A). Children with this mutation are generally asymptomatic unless challenged by a second risk factor, in this case by severe dehydration and diabetic ketoacidosis. Our patient presented a unique diagnostic challenge at the time of her acute neurological deterioration. Rapid, aggressive intervention with super-selective thrombolysis resulted in complete resolution of severe and potentially life devastating neurological symptoms.