Pulmonary alveolar proteinosis (PAP) is a rare disorder in children. This report describes two siblings in whom PAP developed during infancy (three years for the boy and four years two months for the girl). The girl was admitted for chronic respiratory distress. Chest x-ray showed a reticulonodular pattern. Her brother was asymptomatic. The diagnosis of PAP was confirmed by open lung biopsy for the boy and broncho-alveolar lavage for the girl. Therapeutic broncho-alveolar lavages were performed (six for the girl and two for the boy), the girl lost dependence on oxygen therapy. 6 years later, the brother is still asymptomatic. The sister had two episodes of respiratory distress, after two and four years, that required therapeutic lavages. The last therapeutic bronch-oalveolar lavage was performed for the first time by a Tunisian team.