Pulmonary alveolar proteinosis (PAP) is a rare disorder characterised by accumulation of lipoproteinaceous material in the alveolar air spaces. Diagnosis depends on histopathological and radiological features. Treatment includes whole lung lavage (WLL) and GM–CSF therapy. We present a case report of primary idiopathic PAP treated with bilateral whole lung lavage. A 50 year old female presented with history of progressive breathlessness and recurrent lower respiratory tract infection. There were bilateral basal fine crepitations on auscultation and she was maintaining saturation of 70% at room air. Serial chest radiographs showed persistent bilateral alveolar opacities. HRCT thorax showed crazy paving pattern involving both lungs. BAL fluid showed lipoproteinaceous material which was PAS stain positive. Patient was subsequently treated with bilateral WLL following which there was radiological and clinical improvement.