This randomized study compared two ultrasound-guided techniques for placing a peripheral intravenous cannula in adults aged 20 to 60 years who required intravenous access. Participants were assigned equally to either the short-axis out-of-plane approach or the long-axis in-plane approach. The study evaluated whether the techniques differed in successful cannulation. It also compared cannulation time, number of attempts, and immediate complications, including arterial puncture, extravasation, and haematoma.