Abstract: A flashback vent plug is provided for catheters with air vents drilled by a laser beam which allow venting of the hollow plug upon venous entry, but which vents are so small that blood cannot pass. As a result, no leakage ever takes place. As a further feature of the invention, is the addition of a component to the resin making up the vent plug body which optimizes absorption of the laser beam wave length. The air vent design of this invention provides sufficient cross-section for achieving the required air flow, and therefore rapid flashback and venous entry indication, yet its cost of manufacture is considerably reduced when compared to plug designs that involve multi-step assembly.