Preheat the grill to medium-high heat.
Wash the zucchinis thoroughly and slice them lengthwise into half-inch thick strips.
In a bowl, combine the olive oil, salt, black pepper, garlic powder, and dried oregano. Mix well.
Brush the zucchini strips with the olive oil mixture on both sides.
Place the zucchini directly on the grill grates. Grill for 3-4 minutes on each side until grill marks appear and the zucchini is tender.
If desired, drizzle balsamic vinegar over the grilled zucchini before serving for added flavor.
Remove the zucchini from the grill using tongs and transfer to a serving platter.
For added flavor, consider marinating the zucchini in the olive oil mixture for 30 minutes before grilling.
You can also sprinkle fresh herbs like parsley or basil over the finished dish for a fresh touch.