Objective: The aim of this study was to create an animal model of obstructive ventriculomegaly in the fetal lamb at 78 days of gestation by injecting maternal blood into the lateral ventricles under ultrasound guidance. Methods: An endoscope of 1.2 mm housed in a 1.6-mm trocar was introduced into the dilated lateral ventricle. The lambs were sacrificed after delivery. Results: All fetuses diagnosed with ventriculomegaly on ultrasound showed dilatation on the anatomical sections. The ventricles had a dilated aspect when compared to the controls. In 1 fetus the septum between the two ventricles was completely ruptured. Microscopically the ependymal cells were flattened and the cellular lining was disruptured. Conclusion: The model proved suitable for ventriculoscopic examination at 128 days of gestation. This should allow to elaborate further on therapeutic studies in this controversial area.