The lung hypoplasia is a very few frequent entity characterized by a detention in the lung development that leads to a poor development of this organ. Habitually this disease is diagnosed in the childhood and there are very few cases that pass unknown, being detected in the mature age (> 18 years). We present four cases of diagnoses adult patients of lung hypoplasia for diverse test (imaging or invasive) that consulted for not specific symptoms, mostly related with infections of the lung and their later evolution over the years. We also review the pathogenesis, etiology and malformations associated of this disease as well as a review of the published articles in this age group.