An anti-flashback needle adapter inhibits the uncontrolled jetting of blood upon the insertion of an arterial access needle into a blood vessel. An inner wall defines at least one inner port and an outer wall defines at least one outer port in fluid communication with the inner port. As blood enters the device from the arterial access needle, it is diverted first through the inner port and then through the outer port, which diversion has a baffle effect and dissipates the energy of the blood flow. This prevents the jetting of blood and potential contamination of nearby people and objects. A funnel member allows for the insertion of a guide wire into the arterial access needle while maintaining the blood flow dissipation properties of the device.
