Inclusion Criteria:

- Aged ≥18 years.

- Written informed consent.

- With histologically-proven prostate carcinoma.

- ECOG performance status ≤ 2

- Life expectancy > 12 months

- Current or previously documented diagnosis of at least 1 bone metastasis due to
prostate cancer (patient could be hormono naif, Hormono sensible or hormono
refractory)

- Patients with partners of childbearing potential should use a barrier method of
contraception throughout the study.

Exclusion Criteria:

- ECOG performans status >3

- Prior treatment with bisphosphonates IV within the last 3 month to the study

- Renal insufficiency (serum creatinine > 265 micromol/L or > 3.0 mg/dL)

- Liver function tests > 2.5 ULN

- Patients with another nonmalignant disease which would confuse the evaluation of
primary endpoints or prevent the patient from complying with the protocol.

- History of concomitant disease with influence on bone metabolism such as Paget's
disease or primary hyperparathyroidism

- Disabling or non controlled concomitant disease likely to alter the quality of life

- Patient unable to fill in a questionnaire: senile dementia, psychiatric or
neurological disease, illiterate or partially sighted patient

- Known hypersensitivity to zoledronic acid or other bisphosphonates

Other protocol-defined inclusion / exclusion criteria may apply.