A guidewire includes a core shaft and a coil body that covers at least a distal end portion of the core shaft. Along a center line in a longitudinal-axis direction of the core shaft, the distal end portion of the core shaft has a first pre-assembly curvature with respect to a proximal end of the core shaft. Along a center line in a longitudinal-axis direction of the coil body, at least a distal end portion of the coil body has a second pre-assembly curvature with respect to a proximal end of the coil body. The first pre-assembly curvature is less than the second pre-assembly curvature. When the core shaft and the coil body are coupled to each other, a distal end portion of the guidewire has, along a center line in a longitudinal-axis direction of the guidewire, a third curvature with respect to a proximal end of the guidewire.