Prolactinomas are a common cause of gonadal dysfunction and infertility. We present the case of a 38-year-old woman with history of amenorrhea and infertility. At seven weeks of pregnancy she presented neuro-ophthalmologic complaints of headaches, diplopia, and right ptosis. The work-up study revealed an invasive pituitary macroadenoma with a maximum diameter of 9 cm and serum prolactin of 25,800 ng/mL (3-20). At 12 weeks, she was referred to the Endocrinology Department of the Coimbra University Hospital and started therapy with bromocriptine, initially 5 mg/day and then at crescent doses. Hyperprolactinemia was rapidly and drastically reduced to 254 ng/mL three weeks after taking bromocriptine 15 mg/day. Tumoral volume was reduced and there was improvement of III pair paresis. At 38 weeks, a male healthy baby was born. This is a relevant clinical case that illustrates the efficacy and safety of bromocriptine therapy during pregnancy, even in severe cases like this one.