Bring 3 cups water in a medium pot to a boil; add rotini and cook, uncovered, stirring occasionally, until tender yet firm to the bite, about 8 minutes. Drain; cool for 3 minutes.
Place rotini in a serving bowl. Add tomatoes, olive oil, lemon juice, garlic, salt, and black pepper; toss to coat. Add arugula; toss until well combined.
Arugula Pasta Salad · Dinner Match Lab | Dinner Match Lab