Abstract: ? Localization of blood vessels is based on a method and an apparatus having two or more pressure transducers, said apparatus being positioned on the skin over the blood vessel which is to be localized. The signals from the transducers are processed in accordance with the physiological point of departure by mutual weighting. The position of the blood vessel relative to the measuring transducers is found on the basis of a determination of the mass centre of the transducer signals. The transducers used are arranged in parallel in the same plane, but are physically separated by mechanical screens which prevent pressure transfer between two adjacent transducers. A measuring head in which the transducers are arranged is protected by a film of a skin-friendly material, ?ch as e.g. silicone rubber. The apparatuses for blood vessel localization visually inform the user of the position of the measuring ?aratus on the skin of the individual being measured.