This case report describes a 74-year-old woman with obsessive-compulsive behaviors that disappeared following a left capsular genu infarction. The patient's capsular genu infarction likely resulted in thalamocortical disconnection in the cortico-basal ganglia-thalamocortical loop, which may have caused the disappearance of her obsessive-compulsive symptoms. The fact that anterior capsulotomy has been demonstrated to be effective for treating refractory obsessive-compulsive disorder further supports this hypothesis.