Diaphragmatic hernias are an uncommon cause of abdominal pain in horses. The following case report describes a diaphragmatic hernia in 2 adult horses with signs of acute colic. A six-year-old stallion and a seven-year-old mare were referred to the emergency duty for severe abdominal pain; for a six-month period from late 2021 to early 2022. The horses were subjected to explorative laparotomy, which revealed a migration of the large colon associated with volvulus (in stallion); and small intestine protrusion (in mare) in thoracic space. Necropsy revealed a diaphragmatic chronic rupture (approximately 13 centimeters in diameter) in the left mid-region with the protrusion of the large colon in the thoracic cavity in the male horse; and a diaphragmatic acute rupture (approximately 3 centimeters in diameter) in the left dorsolateral region with the incarceration of jejunum in thoracic cavity in the mare. This case report demonstrated that a diaphragmatic hernia should be considered as a differential diagnosis in equine colic.