Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by the accumulation of lipoproteinaceous material within alveolar spaces. Whole-lung lavage (WLL) has been the most common therapeutic intervention for this disorder. However, patients presenting with PAP are usually hypoxemic or in poor clinical condition, and WLL may be impossible to perform. In such cases, multiple segmental lavage (MSL) may be advocated as a first-choice therapy prior to WLL. Herein, we present two cases with idiopathic PAP treated successfully with both lavage techniques consecutively. After the MSL procedure, WLL was performed, and both patients showed a marked clinical and physiologic improvement. Therefore, for patients who are not good candidates for general anesthesia, we recommend MSL (or 'prewash') before WLL to produce an increase in the blood oxygen level for long-duration general anesthesia. In the surgical room, close monitoring and repositioning of the patient as well as maintenance and inspection of the correct tube position, and manual chest wall percussion are extremely important for the safety and success of the procedure.