Sitting craniotomies pose a unique set of problems for perioperative care of the neurosurgical patient. Although there are benefits to neurosurgery in this position, a number of potentially catastrophic complications may also result. This chapter presents a case study of a 20-year-old morbidly obese male presented for resection of a pineocytoma via a supracerebellar approach in the sitting position. The sitting position for craniotomies offers several surgical advantages. Exposure to posterior cervical and posterior fossa structures is improved. It has been suggested that a ventriculo-atrial shunt, pulmonary hypertension, a patent foramen ovale, and symptomatic cerebral ischemia may be absolute contraindications to this procedure. Performing surgery in the sitting position for patients with uncontrolled hypertension, significant chronic obstructive airway disease, or at the extremes of age should also be done with caution. However, there are few data to support appropriate patient selection.