Medical devices, such as stents, and methods of making the devices are disclosed. In some embodiments, a medical device includes an alloy having tantalum, tungsten, zirconium and niobium. For example, the alloy can include from about 20% to about 40% by weight of tantalum, from about 0.5% to about 9% by weight of tungsten, and from about 0.5% to about 10% by weight of zirconium.