Neuroendoscopic third ventriculostomy (NTV) has superseded shunting as the treatment of choice in non-communicating hydrocephalus. Intracranial developmental anomalies have been considered to be relative contraindications for this procedure. We present one patient with a Dandy-Walker malformation and another with septo-optic dysplasia who presented with hydrocephalus. An NTV was performed successfully in both patients using a flexible neuroendoscope and utilising transendoscopic Doppler ultrasound to ensure a safe target area for ventriculostomy.