A catheterization laboratory or cath lab is an examination room in a hospital or clinic with diagnostic imaging equipment used to support the catheterization procedure. A catheter is inserted into a large artery, and various wires and devices can be inserted through the body via the catheter which is inside the artery. The artery most used is the femoral artery.However, the femoral artery is associated with local complication in up to 3% of patients and hence, more interventional physicians are moving towards the radial (wrist) artery, as an alternative site. Disadvantages of the radial artery include small vessel caliber and a different "learning curve" for physicians used to the femoral (groin) access.

Most catheterization laboratories are "single plane" facilities, those that have a single X-ray generator source and an image intensifier. Older cath labs used cine film to record the information obtained, but since 2000, most new facilities are digital. The latest digital cath labs are biplane (have two X-ray sources) and digital, flat panel labs.

Biplane labs achieve two separate planes of view with the same injection and thus save time and limit contrast dye, limiting kidney damage in susceptible patients

Catheterisation laboratories in the UK are staffed by a multidisciplinary team including a Physician (normally either a cardiologist or radiologist), a Cardiac Physiologist, a Nurse and a Radiographer.