Described here are devices and methods for crimping self-expanding devices. The crimping devices may be useful for crimping a variety of different self-expanding devices (whether such devices are biodegradable or bio-durable). The crimping devices may have crimping members to engage the self-expanding device to reduce the device from an expanding configuration to an unexpanded configuration. The crimping member may comprise or include a suture, wire, ribbon, guiding hoop, pusher, prong, holding bar, balloon, jaws, combinations thereof, or the like. The crimping devices may also include or comprise a holding structure to hold the self-expanding device in an unexpanded or expanded configuration.