Preheat grill. Cut potatoes in half. Cut zucchini and sausage the same width as potatoes. Place skewer through potato, zucchini and sausage. Repeat for each skewer.
Place skewer in dish and pour Italian dressing over skewers. Marinate in dressing for 5 minutes.
Place skewers on grill and cook 5 minutes each side, or until potatoes are done. Remove from grill and serve.