Acute lymphocytic leukemia (ALL) is a common pediatric cancer diagnosis with excellent survival outcomes but significant morbidity, particularly during the induction phase of chemotherapy. Central venous sinus thrombosis (CVST) is a known potential complication of induction therapy; however, it occurs rarely and may be difficult to diagnose, particularly in young children who have limited verbal skills. Herein, we report a case of CVST in a child with B-cell ALL undergoing induction chemotherapy whose main symptoms were headache and a change in the appearance of his artwork noticed by his parents. This astute observation by the child's parents played a critical role in his diagnosis, allowing prompt treatment and eventual recovery.