Patients are randomized to 1 of 2 treatment arms. Treatment continues in the absence of disease progression or a skeletal-related event. All patients receive concurrent androgen deprivation therapy with a GnRH agonist. Patients also receive oral calcium and (vitamin D) supplements daily. Patients progressing to androgen-independent prostate cancer proceed to the open-label therapy with zoledronic acid IV. Treatment continues for 3 weeks in the absence of disease progression or the first skeletal-related event.