A vaso-occlusive implant has a primary helical-coil shape that defines a primary axis and a three-dimensional secondary shape. The secondary shape includes a substantially helical section and a second section having a plurality of non-overlapping loops or loop sections. Each loop defines a plane that is oriented at an angle from about 30-150 degrees relative to a plane defined by an immediately preceding or immediately succeeding loop along the primary axis. The coil sections or loops can be generally circular loops or other smooth shapes.