PURPOSE: Platinum compounds are very effective drugs for the treatment of childhood malignancies, and their use has contributed to an increase in the long-term survival of children with cancer. Unfortunately, the risk of severe disabling effects such as nephrotoxicity is well known among children receiving cisplatin-based chemotherapy. METHODS: The main pharmacodynamics and clinical characteristics of cisplatin nephrotoxicity are described in order to explore the real ability of mannitol to prevent cisplatin-related nephrotoxicity. RESULTS: Currently, the choice of hydration alone or hydration plus mannitol to prevent nephrotoxicity is controversial. No guidelines are available to provide recommendations on this issue either in adults or in children. CONCLUSIONS: Appropriate hydration remains the main fundamental strategy for reducing the risk of cisplatin-induced nephrotoxicity. In conventional treatment regimens employing doses of cisplatin of less than 100 mg/m(2) in patients with normal renal function, pre- and post-hydration (3 l/m(2) at least 12 h pre-cisplatin and 24 h post-cisplatin) alone should be routinely used. In higher doses, pre- and post-hydration plus mannitol should be considered in order to ensure a valid diuresis.