Pulmonary alveolar proteinosis (PAP) is a rare disease in infancy, resulting from abnormalities of surfactant production or decreased catabolism of surfactant. The only effective treatment of the congenital form of PAP is bronchoalveolar lavage. A 4-month-old boy with severe PAP received bilateral partial lung lavage on two occasions resulting in clinical improvement. We performed partial lung lavage using a 3.1 mm flexible fibreoptic bronchoscope introduced through a 4.0 mm tracheal tube under general anaesthesia. The infant did not require extra-corporeal oxygenation during the procedure or postoperative ventilation. This method may offer a feasible option for performing lavage in a resource constrained environment.