An intravenous catheter introducer for medical use having a body, a frontal attachment that is disposed in transverse sliding engagement with a front part of the body, a hub tube assembly that is releasably supported by the frontal attachment, and a retractable catheter insertion needle and needle holder that are biased rearwardly by a spring offset laterally from the needle axis, whereby lateral repositioning of the body relative to the frontal attachment following vascular insertion moves a needle retraction cavity disposed inside the body into substantial coaxial alignment and causes the needle holder to be retracted into the needle retraction cavity.