A port-a-cath is a small medical appliance that is installed beneath the skin. It allows drugs or nutrients to be administered to the blood stream and is particular benefit to those whose veins are difficult to find.

In the device a catheter connects the port to a vein. Under the skin, the port has an area through which drugs can be injected and blood samples can be drawn many times, usually with less discomfort for the patient than a more typical needle prick.

A port is a reservoir compartment (the portal) that has a silicone bubble for needle insertion, with an attached plastic tube (the catheter). The device is surgically inserted under the skin in the upper chest or in the arm and appears as a bump under the skin. It requires no special maintenance and is completely internal so swimming and bathing are not a problem. The catheter runs from the portal and is surgically inserted into a vein. Surgery is required to place the implant and remove it.

Ports are used mostly by haematology and oncology patients and recently have been adapted for haemodialysis patients.