A guidewire assembly having selectively adjustable stiffness and tip curvature includes a hollow guidewire having a distal portion terminating at a distal tip, a curvature-modifying element anchored to the distal tip, and a stiffness-modifying element displaceable within the hollow guidewire towards and away from the distal tip so as to vary a stiffness of the distal portion. The stiffness-modifying element and the curvature-modifying element are frictionally linked such that movement of the stiffness-modifying element from a current position over a first range of motion causes corresponding displacement of the curvature-modifying element, thereby modifying a state of curvature of at least part of the distal portion of the guidewire. Movement of the stiffness-modifying element beyond the first range of motion displaces the stiffness-modifying element relative to the curvature-modifying element.