Objective: Rare disease Background: Primary pituitary tuberculosis (in absence of other organ involvement and constitutional symptoms) is an extremely rare disease with total reported cases in the literature fewer than a hundred. Misdiagnosis as pituitary adenoma is common and late diagnosis can result in a permanent endocrine dysfunction and/or long-term neurologic sequelae. Case Report: We report on the case of a middle-aged woman who presented with severe headache and left third cranial nerve palsy. Magnetic resonance imaging (MRI) revealed a large pituitary tumor invading the left cavernous sinus. The case was initially misdiagnosed as pituitary adenoma. A pituitary biopsy was performed and was suggestive of pituitary tuberculosis. Extensive radiologic investigations did not reveal any evidence of other organ involvement by tuberculosis. She was successfully treated with anti-tuberculous medications. Conclusions: In areas with a high pre-test probability of tuberculosis, pituitary tuberculosis should be included in the differential diagnosis of pituitary tumors in order to avoid unnecessary surgical interventions. Besides being the first histologically-proven primary pituitary tuberculosis case reported from Qatar, the current case is unique in that extensive radiologic investigations did not reveal any evidence of other systemic or pulmonary tuberculosis.