Pituitary apoplexy can occur as a complication of idiopathic thrombocytopenic purpura. We report here a new case of such association. A male patient aged 59 years, complaining of decreased libido for one year, was referred to the emergency department for purpura and severe thrombocytopenia (4000 platelets/mm3). 24 hours after the cutaneous rash the patient presented with clinical symptoms of bilateral cavernous sinus compression comprising ptosis, bilateral ophtalmoplegia and right supraorbital hypoesthesia. Cranial CT scan showed an enlarged sella and a pituitary mass with signs of intrapituitary haemorrhage. Hormonal evaluation showed hyperprolactinemia (50 ng/mL) and hypopituitarism, and the patient needed substitution with hydrocortisone and levothyroxine. Immunoglobulins and corticosteroids were given to the patient to treat thrombocytopenia, then worsening of neurological and ophtalmological symptoms led to pituitary surgery. Histopathological examination found necrotical pituitary tissue. Immunostaining with an anti-prolactin antibody was positive in several groups of cells. Neurological symptoms subsided and thrombocytopenia was corrected by treatment. In conclusion, we report a case of pituitary apoplexy due to severe thrombocytopenia occurring as a complication of a preexisting macroprolactinoma.