Preheat oven to 400°F (200°C) and line a baking sheet with parchment paper.
Slice the potatoes and kielbasa into rings and place them in a large mixing bowl.
Drizzle with olive oil and season with salt, garlic, and parsley. Toss everything to coat evenly.
Spread the mixture in a single layer on the prepared baking sheet.
Roast for 40 minutes, flipping halfway, until the potatoes are golden and crispy.
Check for doneness—potatoes should be fork-tender, and kielbasa should be slightly caramelized.
Remove from oven and let cool for a couple of minutes before serving.
Garnish with fresh parsley and serve hot with your favorite side dish.