Butterfly needles, also known as winged infusion sets, are a very common needle style used to collect blood during a venipuncture. The butterfly needle consists of the stainless steel collection needle fitted with flexible “wings,” which the phlebotomist uses to grip the needle, and a valve that attaches to a tube, through which blood drawn flows into a collection tube. Butterfly needles are popular because of their ease-of-use, and their size makes them an optimal choice for drawing blood from children or geriatric patients.

Greet patient, then wash hands with soap and water. Allow hands to dry before putting on gloves and any other required personal protective equipment.

Remove butterfly needle from packaging. Straighten out tubing and attach the valve (also called the Luer adapter) to a fresh tube holder.

Choose the correct blood collection tube(s) based on the types of blood tests ordered. Place the blood collection tube into the tube holder without breaking the vacuum seal.

Warm the patient's elbow crease with the portable, single use-warming device to aid in locating a vein.

Tie the tourniquet on the patient's arm above the elbow crease and locate (palpitate) a vein. Note the vein’s depth and direction.

Swab the patient’s elbow crease with an alcohol swab. Allow alcohol to dry completely.

Pick up butterfly needle by its wings. One side of the wings will be textured for grip. Pinch the wings between your thumb and first finger and remove needle cap.

With your free hand, anchor the chosen vein and position the needle so that it is running parallel to the direction of the vein.

Insert the needle quickly, matching the depth of the vein with your angle of insertion (should be between 15 degrees and 30 degrees). You will feel a pop as you puncture the skin and a second pop and you enter the vein.

Press the blood collection tube down into the tube holder and look for a flash of blood in the tubing attached to the needle. If you do not see this flash and blood does not flow into the tube, carefully try repositioning the needle.

Untie and remove the tourniquet once blood has begun flowing into the tube. If you have multiple tubes to fill, you can gently use surgical tape to secure the needle by the wings so that it doesn’t move around on the patient.

Complete the rest of the venipuncture procedure, remove needle and activate the safety device on the needle to retract it. Bandage patient's arm and dispose of the needle carefully in a sharps container.


Needlestick injury risk is very high when using butterfly needles. Be sure to handle them carefully and always retract them using the safety device after removal.