A device for occluding a septal defect is provided. In general, the occluding device has a contracted state that allows the occluding device to be received within a delivery device for deployment to the site of the defect and an expanded state that is achieved when the occluding device is deployed from the delivery device. The occluding device has a proximal portion, which may be substantially circular, a distal portion, which may be substantially ovaloid, and a connecting portion extending between the two. The distal portion may define first and second outer parts at opposite ends of the major axis, which may be bent or curved. The configuration of the proximal and distal portions allow the occluding device to securely engage the septal wall and be kept in position at the septal defect without causing substantial interference with the functioning of adjacent heart structures.