Optically transparent fluids were investigated as a means of transmitting laser energy (LE) in laser angioplasty catheters as an alternative to fused silica fibers. A catheter was constructed which transmits LE through a flowing stream of iodinated contrast media. LE is launched into a stream of contrast media and is internally reflected by a lower index of refraction cladding-providing transmission efficiency of 75%. As the stream exits the catheter, blood acts as an optical cladding and allows transmission 1 cm distal to the catheter tip. The low pressure stream removes intervening blood and provides an atraumatic surface for light interaction with target tissues. Fluoroscopy of the contrast stream allows real-time visualization of the catheter, the site of LE delivery and distal vasculature. We conclude that a fluid-core laser angioplasty catheter can transmit high peak-power laser energy and offers simplicity, blood removal, improved flexibility and real-time imaging during intravascular LE delivery.