If using bamboo skewers, get them soaking in water to prevent burning.
Chop off the ends of your zucchinis. Using a mandolin, slice zucchini very thin. Slide the end of the zucchini slice onto the skewer and add a tomato. Fold the zucchini back onto the skewer over the tomato. Add another tomato and repeat the process. When you run out of zucchini, add another slice and continue.
Heat the grill to high. Spritz the kebabs with oil and place onto the grate. Cook 20 minutes, rotating every 5 minutes. Spray lightly with oil each time you rotate.
Remove from grill and enjoy!