Failure of neural crest cells to migrate from neural crests during intrauterine development result in partial or total aganglionosis of the colon in newborn. Hirschprung's disease (HD) represents the clinical manifestation of this pathogenic process, currently accounting for the majority of lower intestinal obstruction in the first period of life. Our aim was to present a series of three cases presenting to our tertiary care center with a range of symptoms, all benefiting from surgery and consequent pathology examination of biopsy or resection pieces. The first case was of a male newborn that presented several years ago with common symptoms for HD (abdominal distension, vomiting and the total lack of intestinal passage for feces). Coming from young healthy parents after normal labor, the newborn displayed signs of Down's disease after physical examination. After abdominal radiography, the patient underwent surgery and consecutive pathology revealed notable signs of Crohn's disease (CD): massive stasis in the serosa and submucosa, chronic inflammatory infiltrate and lack of nervous cells in both plexuses and mucosa. Immunohistochemistry revealed low intensity CD34 membrane staining for fibroblast-like ganglion cells while CD117 staining showed few nervous cells within the mucosa. The second case presented before one year of age with an infectious background, already being operated upon with colostoma. We performed corrective surgery of the colostoma and consecutive pathology showed low CD117 cytoplasmic staining and intensely positive NSE (neuron specific enolase) staining within myenteric plexuses. Finally, the third and most recent case was that of a 4-year-old boy with an early diagnosis of megacolon and no previous surgery, who we evaluated by laparoscopy with five biopsies and consecutive S100 staining revealed a small number of nervous cells within nervous plexuses. In conclusion, an early diagnosis of HD is essential for successful therapeutic measures. Histology and, more recently, immunohistochemistry, represent the gold-standard procedures needed to objectify the diagnosis.