Pulmonary alveolar proteinosis (PAP) is a rare syndrome characterised by intra-alveolar accumulation of surfactant components and cellular debris, with minimal interstitial inflammation or fibrosis. Since surfactant accumulates abnormally, a disturbance in the normal pathway of surfactant production, metabolism, recycling or degradation has been postulated. This disease has a variable clinical course: from spontaneous resolution to respiratory failure and death due to disease progression or superimposed infections. PAP leading to pulmonary fibrosis is rarely seen, and few case reports describe this association. Here, we describe the case of a patient with a diagnosis of PAP confirmed by open lung biopsy, who developed interstitial pulmonary fibrosis years after disease onset.