To maximize the benefit and minimize the adverse effects of fluid and electrolyte therapy, it is critical for clinicians involved to be knowledgeable about the use of parenteral fluids as maintenance therapy, replacement therapy, or as a vehicle for drug administration. All clinicians involved in the administration of parenteral therapy must understand the physiologic processes that regulate fluid and electrolyte balance, the proper dosing of these nutrients, and the fluids used to manage patients' fluid and electrolyte balance. The role of i.v. solutions in fluid and electrolyte balance is reviewed, and the value of the i.v. nurse specialist as a member of the interdisciplinary team that safely and effectively administers fluid and electrolyte therapy is highlighted.