Objective To identify the most common causes of diffuse alveolar hemorrhage (DAH) and the evolution of cases during hospitalization. Patients and methods A review of cases diagnosed with DAH; the diagnoses were classified according to existing criteria and the progression of the cases was determined. Results We identified 17 cases of DAH, with the leading cause being ANCA associated vasculitis (41% of cases), followed by cases secondary to drugs (18%). In 35% of the cases, there was a failure in identifying an etiology. Six patients died (35%), the only factor associated with mortality was male gender 5/6 vs 3/11, p=0.05. Conclusions The most frequent cause of alveolar hemorrhage was ANCA associated vasculitis. The mortality in DAH is about 35%, males seem to have a worse prognosis.