Physiologic pituitary enlargement is common during normal pregnancy. However, symptoms such as diplopia, blurred vision and headache resulting from physiologic pituitary enlargement are very rare during pregnancy. A 43-year-old woman complained of sudden headache and left eye ptosis at 36th weeks of gestation. An magnetic resonance imaging (MRI) demonstrated the pituitary enlargement and a macroadenoma without a compressing of the optic chiasm, but with an extension to the left cavernous sinus. 48 hours after the prescription of the bromocriptine, we had a spectacular evolution with disappearance of the headache and a total regression of the ptosis. We report a case of visual loss due to the physiologic pituitary enlargement or to the macroadenoma during pregnancy, which regressed after the prescription of bromocroptine.