Pulmonary alveolar microlithiasis (PAM) is a rare disease of unknown etiology, characterized by the presence of calcific concretions in the alveolar spaces. A familial occurrence is frequently found so that an inherited trait is thought to be involved. The chest X-ray is characterized by a 'sandstrom' picture while the clinical state undergoes to a slow and progressive impairment resulting in respiratory failure at the end stage. We have reviewed the Italian literature of the past 50 years detecting 48 case-reports of PAM (19 males and 29 females). Only 20 out of them were documented in international journals. A familial occurrence of 43.7% was found and 18 patients were under age fifteen. There was a prevalence in the female sex (60.4%) and in the second decade of life. Chest X-ray was the most important tool to diagnose PAM revealing the characteristic picture in all patient. Bronchoalveolar lavage (BAL) and open lung biopsy respectively show the characteristic calcospherites in the recovered fluid (BALF) and in the alveolar spaces. About 300 cases of PAM are reported in the international literature. We believe these data are probably underestimated because many case-reports are not published in international literature.