['Alterations of sperm number and motility are found in hyperprolactinaemic men. Cabergoline treatment reverses alterations in semen. No information is currently available on the quality of seminal tests in hyperprolactinemia in response to cabergoline treatment.', 'To further investigate the effect of hyperprolactinaemia and its treatment with cabergoline on semen quality.', 'Forty-three men with hyperprolactinaemia (32 macro- and 11 micro-prolactinomas); 60 healthy men served as control.', 'Live spermatozoa count, sperm membrane function, kinetic index, nuclear DNA integrity, sperm curvilinear and linear velocity and amplitude of lateral movement of the sperm head were investigated before and after 6 and 24 months of treatment with cabergoline.', 'Open prospective.', 'At study entry, semen functional tests were severely and similarly impaired both in patients with macro- and micro-prolactinomas compared to controls. After 6 and 12 months of treatment there was a significant improvement of semen quality in patients achieving normalization of prolactin levels, although most of the parameters remained lower than in controls. After 24 months of treatment, seminal fluid characteristics were similar to the controls except for live spermatozoa count, sperm membrane function, sperm kinetic index and sperm nuclear DNA integrity, which remained abnormal in 9.3-53% of the patients.'] Does the treatment with cabergoline for 24 month normalize the quality of seminal fluid in hyperprolactinaemic males?