SummaryA total of 103 intravenous infusions were studied to identify factors related to infiltration. Findings suggested that infiltration was related to 1) length of needle—none of the infusions started with a 1 1/2-inch needle infiltrated, whereas 21 out of 83 started with a 1-inch needle infiltrated; 2) activity of the patient; and 3) above average amount of nonprofessional nursing hours. No significant relationship was found between infiltration and site of the infusion (hand or antecubital fossa); method of taping the needle; gauge of needle, vein condition; sex or age of patient; and length or number of infusions.Other factors which might influence infiltration and which also warrant study are: 1) the interrelationship of needle length and needle gauge, 2) bevel length, and 31 interrelationship between upper extremity infusion site and handedness of the patient. The present study has pointed out variables that need to be subjected to controlled research to determine the relationship to infiltration.