Abstract: A needle guide system for use with an ultrasound probe, the system comprising a surface marking guide and a needle guide. The surface marking guide includes an attachment portion for attaching the marking guide to an ultrasound probe, and a surface contact portion fixed to the attachment portion and including one or more features for identifying to a user where to mark a surface when the ultrasound probe is held against the surface. The needle guide includes a base to support the needle guide on the surface, one or more features on the base for alignment with marks made on the surface, and a needle support mounted on the base and having a needle channel through which a needle can extend, the needle channel having a known position and orientation relative to the base. We also describe a needle guide for use with an ultrasound probe to guide a needle along a predetermined path relative to the ultrasound probe.