Introduction: Advances in prenatal imaging studies have allowed early diagnosis of Congenital Diaphragmatic Hernia (CDH), although neonatal mortality remains at high levels (60% survival). Despite advances, this study found delayed diagnosis, demonstrating subdiagnosis, possibly caused by lack of resources and/or prenatal diagnostic failure. Case Report 1: Infant, 4 months and 22 days old, dyspneic, cyanotic, with fever and vomiting for 3 days, treated as pneumonia. After the second chest radiography, a right CDH was revealed. Surgical correction was performed and removal of Meckel’s diverticulum was surgical findings. The patient was discharged on the 10th days after admission. Case Report 2: Infant, 11 months and 3 days old, distended abdomen, with fever and dyspnea for 2 days, treated as pneumonia. After the second chest radiography, a left CDH was revealed. The patient was submitted to surgery, intestinal loop incarceration without necrosis was observed, and the correction of CDH was performed. The patient was discharged on the 7th day after admission. Discussion: Three cases, between July 2012 and July 2013, were diagnosed at Dom Malam Hospital; 2 Cases of CDH, with delayed diagnosis, showed incidence of 66.66%. Delayed diagnosis of these patients with initial hypotheses of pneumonia demonstrated high risk, emphasizing the importance of diagnosis research through observation of the clinical course, the correct imaging interpretation, in order to establish early diagnosis and treatment.