Granulosa cell tumours are commonly identified in mares, but have rarely been identified in equine neonates. This report describes a septic neonatal foal that presented with haemoabdomen secondary to a ruptured ovarian granulosa cell tumour. The ultrasonographic appearance, successful surgical removal and histopathological appearance of the tumour is described. Juvenile ovarian granulosa cell tumours differ histologically from adult granulosa cell tumours. Ultrasound is a useful way to identify haemoabdomen and abdominal masses in foals. Juvenile granulosa cell tumour should be considered as a differential for this combination in neonatal foals.