The Authors have treated 11 patients with benign breast diseases (fibroadenosis or fibrocystic disease) with two prolactin inhibitor drugs -- metergoline and bromocriptine -- at the dose of 8 mg/die and 7,5 mg/die respectively for sixty days with a 30 days interval from one to the other. All patients, except one, had normal serum prolactin levels before the trial; during the treatment with metergoline no long-term changes in serum prolactin levels were observed; on the contrary, bromocriptine reduced significantly prolactin values for the whole duration of the therapy. Negative clinical results were obtained with the first drug, while bromocriptine allowed to reach an 80% of positive results at the end of the trial. Coming from previous experience, the Authors conclude that the positive therapeutic effect of bromocriptine treatment is connected with the maintenance of prolactin reduction.