|Enabled by current high-speed networks, high-definition (HD) video transmissions have become an essential tool for many applications. The HD video brings resolution, which is more than 4x larger than common PAL resolution, thus capturing much more details and increasing the image quality dramatically. In this talk, we would like to focus on using the HD video for two classes of medical applications: synchronous applications, which require low latency to provide perception of interactivity, and asynchronous (unidirectional) applications, where the latency is not that restrictive. We will describe (and possibly also demonstrate) uncompressed HD over IP transmission in both point-to-point (two colleagues consulting) and multipoint-to-multipoint (council) modes, suitable for synchronous environments with exceptional requirements on low latency. The uncompressed HD video is very challenging regarding capabilities of the underlying networks having 1.5Gbps bandwidth per stream; we will discuss how to utilize current high-end optical networking to create suitable environment. We will brief compression technologies, that allow transmitting HD video without extreme networking requirements while maintaining high image quality at cost of increased latency. We will describe HDV over IP transmission suitable for unidirectional HD video distribution (e.g. streaming for students) with 30 Mbps bandwidth per stream, that can be implemented relatively cheaply using easily available equipment.