We present a case of transmesenteric hernia resulting in the death of a 3-month-old female infant, the seventh such autopsy case reported so far. A three-month-old female infant, who initially presented with two episodes of vomiting, cramps, and constipation, was admitted to the hospital. She received symptomatic therapy and was released home. Immediately after she had been put to bed at home, she stopped breathing. There was no record of previous illnesses in the infant's medical history. At autopsy, a necrotic segment of ileum and jejunum, length about 50 cm, was found herniated through an oval defect in the mesentery and multiply strangulated. The shock caused by small intestinal obstruction with consequent intestinal necrosis due to strangulation of the small intestine through a congenital mesenteric defect was considered to be the cause of death. In clinical practice, cases of transmesenteric hernias are uncommon, especially in the population of infants and toddlers; however, these can potentially be the cause of serious intestinal obstruction, with a high mortality rate in cases left untreated. Despite the low incidence of this condition, we believe that the clinicians should keep this diagnosis in mind as a potential cause of acute abdomen and pay special attention to revealing the cause of presented symptoms.