Vascular needle system for visualisation of blood comprising a vascular needle (2) comprising a tube having a bevelled distal end (5) and a proximal end (4) and between said ends a tubular wall having an external surface and an axial cavity for the passage of a fluid between said ends, said needle (2) being provided with at least one lateral aperture (6) and a proximal base-body (3), said vascular needle system also comprising a plastic transparent tubular cannula (1) having an internal surface and overlying at least partially said needle (2).