Objectives: To evaluate treatment effect of acute mastoiditis. Methods: Retrospective study, 52 patients were diagnosed acute otomastoiditis and treated in National ENT hospital from January 2009 to December 2011. Results: Antibiotics: Cephalosporin III (86.5 percent), Amoxicillin + acid clavulinic (13.5 percent). Surgery: 10/52 had mastoidectomy, 14/52 had mastoidectomy with PE tube placed, 9/52 had PE tube, 19/52 received medical therapy. Averaged hospitalized time was 11.9 days. Conclusions: 100 percent treated with antibiotics, most of surgery were mastoidectomy with/without tympanostomy tube. Acute mastoiditis without osteitis or complication could be treated with medical therapy with/not tympanostomy.