Video-UDS is a special technique wherein i-UDS and MCU are performed simultaneously to allow functional and anatomical assessment of the bladder and urethra at the same time. It has a special role in cases of VUR where we need to differentiate between primary and secondary VUR or assess the bladder behaviour in patients with gross VUR. It may also be indicated in children with complex voiding problems or outflow tract obstruction with unknown aetiology. Many centres advocate performance of video-UDS instead of MCU alone. This chapter outlines the practical aspects of performing a video-UDS study followed by a few case scenarios showing the utility of the study.