This paper presents a clinical case of persistent hyperinsulinemic hypoglycemia of infancy (PHHI) and a literature review on this subject. We report on a newborn who presented with hypoglycemic episodes in her first 24 hs of life and was treated successfully with octreotide until the moment. PHHI is the most common cause of persistent hyperinsulinism in infancy and can be hazardous for the development of the central nervous system. There are few current options for clinical treatment, with variable efficacy, and octreotide seems to be the best option before surgical treatment, the only way to control the disease. Preoperative evaluation allows one to adequately distinguish between focal or diffuse processes and suggests the extension of pancreatic resection, improving surgical results and reducing the incidence of postoperative sequelae. Partial pancreatectomy is the procedure of choice in focal disease.